The two rows below should look identical. In both, the spanning cells in columns 2-3 should consume as
much width as possible, while column 1 should be tiny.
<table border=2 width=100%>
<tr>
<td>1<td colspan=2>2-3
</tr>
<tr>
<td>1</td>
<td colspan=2 width=100%>2-3</td>
</tr>
</table>