You can use the col element as specified in HTML 4.0 (link). It works in every browser. You can give it an ID or a class or an inline style. only caveat is that it affects the whole column across all rows. Example:
<table>
<col />
<col width="50" />
<col id="anId" />
<col class="whatever" />
<col style="border:1px solid #000;" />
<tbody>
<tr>
<td>One</td>
<td>Two</td>
<td>Three</td>
<td>Four</td>
<td>Five</td>
</tr>
</tbody>
</table>