you can see the solution on http://jsfiddle.net/CBQCA/1/
OR
<table style="height:100%;width:100%; position: absolute; top: 0; bottom: 0; left: 0; right: 0;border:1px solid">
<tr style="height: 25%;">
<td>Region</td>
</tr>
<tr style="height: 75%;">
<td>100.00%</td>
</tr>
</table>?
I removed the font size, to show that columns are expanded.
I added border:1px solid
just to make sure table is expanded. you can remove it.