Det här kanske funkar?
<td> <--- td'n i din andra tabell
<table style="height: 100%" cellpadding="0" cellspacing="0" border="0">
<tr valign="top">
<td>
<img src="foo.gif">
</td>
</tr>
<tr valign="bottom">
<td>
<img src="foo.gif">
</td>
</tr>
</table>
</td>
