<?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>135 - Disclosure - Senior notes (Tables)</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

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&lt;p style="MARGIN-TOP: 12px; TEXT-INDENT: 4%; MARGIN-BOTTOM: 0px"&gt;
&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;At any time and
from time to time on or after May&amp;#xA0;1, 2014, the Company may
redeem the Notes, in whole or in part, at a redemption price equal
to the percentage of principal amount set forth below plus accrued
and unpaid interest to the redemption date:&lt;/font&gt;&lt;/p&gt;
&lt;p style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; FONT-SIZE: 12px"&gt;
&amp;#xA0;&lt;/p&gt;
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&lt;tr&gt;
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&lt;td&gt;&lt;/td&gt;
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&lt;p style="BORDER-BOTTOM: #000000 1px solid; WIDTH: 103pt"&gt;
&lt;font style="FONT-FAMILY: Times New Roman" size="1"&gt;&lt;b&gt;12-Month
period commencing&lt;/b&gt;&lt;/font&gt;&lt;/p&gt;
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&lt;p style="TEXT-INDENT: -1em; MARGIN-LEFT: 1em"&gt;&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;On or after May&amp;#xA0;1,
2014&lt;/font&gt;&lt;/p&gt;
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&lt;td valign="bottom" align="right"&gt;&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;104.5&lt;/font&gt;&lt;/td&gt;
&lt;td valign="bottom" nowrap="nowrap"&gt;&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;%&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
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&lt;p style="TEXT-INDENT: -1em; MARGIN-LEFT: 1em"&gt;&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;On or after May&amp;#xA0;1,
2015 and thereafter&lt;/font&gt;&lt;/p&gt;
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&lt;td valign="bottom" align="right"&gt;&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;100.0&lt;/font&gt;&lt;/td&gt;
&lt;td valign="bottom" nowrap="nowrap"&gt;&lt;font style="FONT-FAMILY: Times New Roman" size="2"&gt;%&amp;#xA0;&lt;/font&gt;&lt;/td&gt;
&lt;/tr&gt;
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