<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>0036 - Disclosure - 18a. INCOME TAXES (Tables)</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName /><CurrencySymbol /><contextRef><ContextID>From2011-10-01to2012-09-30</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001074828</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2011-10-01T00:00:00</PeriodStartDate><PeriodEndDate>2012-09-30T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="12 Months Ended" /><Label Key="Calendar" Id="1" Label="Sep. 30, 2012" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>us-gaap_IncomeTaxDisclosureAbstract</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Income Tax Disclosure [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>
</LabelSeparator><Level>2</Level><ElementName>VSUL_PrincipalComponentsOfCompanysDeferredTaxAssets</ElementName><ElementPrefix>VSUL_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="From2011-10-01to2012-09-30" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0"&gt;The principal components of the Company&amp;#146;s deferredtax assets at September 30, 2012 are as follows:&lt;/p&gt;

&lt;p style="font: 12pt/normal Times New Roman, Times, Serif; margin: 0"&gt;&amp;#160;&lt;/p&gt;

&lt;table align="center" cellspacing="0" cellpadding="0" style="font: 8pt Times New Roman, Times, Serif; width: 100%"&gt;
&lt;tr style="vertical-align: bottom"&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td colspan="2" style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: center"&gt;2012&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td colspan="2" style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: center"&gt;2011&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="width: 64%; line-height: 115%"&gt;U.S. operations loss carry forward at statutory rate of 42.6%&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%"&gt;$&lt;/td&gt;
    &lt;td style="width: 15%; line-height: 115%; text-align: right"&gt;(1,163,832&lt;/td&gt;
    &lt;td nowrap="nowrap" style="width: 1%; line-height: 115%"&gt;)&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%"&gt;$&lt;/td&gt;
    &lt;td style="width: 15%; line-height: 115%; text-align: right"&gt;(1,151,090&lt;/td&gt;
    &lt;td nowrap="nowrap" style="width: 1%; line-height: 115%"&gt;)&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: white"&gt;
    &lt;td style="line-height: 115%"&gt;Less Valuation Allowance&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;1,163,832&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;1,151,090&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="line-height: 115%"&gt;Net Deferred Tax Assets&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: right"&gt;-&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: right"&gt;-&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="background-color: white"&gt;
    &lt;td style="vertical-align: bottom; line-height: 115%"&gt;Change in Valuation allowance&lt;/td&gt;
    &lt;td style="vertical-align: bottom; line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="vertical-align: bottom; border-bottom: black 2.25pt double; line-height: 115%"&gt;$&lt;/td&gt;
    &lt;td style="vertical-align: bottom; border-bottom: black 2.25pt double; line-height: 115%; text-align: right"&gt;-&lt;/td&gt;
    &lt;td nowrap="nowrap" style="vertical-align: bottom; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="vertical-align: bottom; line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="vertical-align: bottom; border-bottom: black 2.25pt double; line-height: 115%"&gt;$&lt;/td&gt;
    &lt;td style="vertical-align: bottom; border-bottom: black 2.25pt double; line-height: 115%; text-align: right"&gt;-&lt;br style="mso-special-character: line-break" /&gt; &lt;br style="mso-special-character: line-break" /&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;
&lt;p style="font: 11pt/115% Calibri, Helvetica, Sans-Serif; margin: 0 0 10pt"&gt;&lt;/p&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>Custom Element.</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Principal components of the Companys deferred tax assets</Label></Row><Row FlagID="0"><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>VSUL_ReconciliationOfUnitedStatesFederalStatutoryRateToCompanysEffectiveTaxRateTableTextBlock</ElementName><ElementPrefix>VSUL_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="From2011-10-01to2012-09-30" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p style="margin: 0pt"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 10pt/normal Times New Roman, Times, Serif; margin: 0"&gt;&lt;/p&gt;

&lt;p style="font: 8pt/115% Times New Roman, Times, Serif; margin: 0 0 10pt"&gt;&lt;font style="background-color: white"&gt;A reconciliation
of the United States Federal Statutory rate to the Company&amp;#146;s effective tax rate for the period ended September 30, 2012
and 2011 is as follows:&lt;/font&gt;&lt;/p&gt;

&lt;p style="font: 10pt/normal Times New Roman, Times, Serif; margin: 0"&gt;&lt;/p&gt;

&lt;table align="center" cellspacing="0" cellpadding="0" style="font: 8pt Times New Roman, Times, Serif; width: 100%"&gt;
&lt;tr style="vertical-align: bottom"&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td colspan="2" style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: center"&gt;2012&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td colspan="2" style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: center"&gt;2011&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="width: 64%; line-height: 115%"&gt;Federal Statutory Rate&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 15%; line-height: 115%; text-align: right"&gt;-42.6&lt;/td&gt;
    &lt;td nowrap="nowrap" style="width: 1%; line-height: 115%"&gt;%&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 1%; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 15%; line-height: 115%; text-align: right"&gt;-42.6&lt;/td&gt;
    &lt;td nowrap="nowrap" style="width: 1%; line-height: 115%"&gt;%&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: white"&gt;
    &lt;td style="line-height: 115%"&gt;Increase in Income Taxes Resulting from:&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;&amp;#160;&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: #CCEEFF"&gt;
    &lt;td style="line-height: 115%"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;Change in Valuation allowance&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: right"&gt;42.6&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;%&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 1.5pt solid; line-height: 115%; text-align: right"&gt;42.6&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;%&lt;/td&gt;&lt;/tr&gt;
&lt;tr style="vertical-align: bottom; background-color: white"&gt;
    &lt;td style="line-height: 115%"&gt;Effective Tax Rate&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 2.25pt double; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 2.25pt double; line-height: 115%; text-align: right"&gt;0.0&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;%&lt;/td&gt;
    &lt;td style="line-height: 115%; text-align: right"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 2.25pt double; line-height: 115%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="border-bottom: black 2.25pt double; line-height: 115%; text-align: right"&gt;0.0&lt;/td&gt;
    &lt;td nowrap="nowrap" style="line-height: 115%"&gt;%&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;
&lt;p style="font: 11pt/115% Calibri, Helvetica, Sans-Serif; margin: 0 0 10pt"&gt;&lt;/p&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>Custom Element.</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>A reconciliation of the United States Federal Statutory rate to the Companys effective tax rate</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>18a. INCOME TAXES (Tables)</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>true</HasCustomUnits><IsEmbedReport>false</IsEmbedReport><IsMultiCurrency>false</IsMultiCurrency><ReportType>Sheet</ReportType><RoleURI>http://visualant.net/role/A.IncomeTaxesTables</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>3</NumberOfRows></InstanceReport>
