Try plugging your info into this nested table
<table width="725" border="0" cellspacing="3" cellpadding="3" align="center">
<tr>
<td><table width="350" border="0" align="center" cellpadding="3" cellspacing="3">
<tr>
<td align="center">This is your first nested table</td>
</tr>
</table></td>
<td><table width="350" border="0" cellspacing="3" cellpadding="3">
<tr>
<td align="center">This is your second nested table</td>
</tr>
</table></td>
</tr>
</table>
Fyi, I looked at your source code, and I really recommend that you not use percentages to determine table width. Use pixels. You will have better results with tables in all browsers, monitor sizes, etc, the more exact you are.