Customizations like this should be done using a combination of roles (which become CSS classes) and a custom stylesheet. For instance, let's say you want to create an pricing table.
[.pricing,grid=all,frame=topbot,width=auto]
|===
|Standard
|1 Database
|5GB Storage
|20 Users
|===
That gives you:
[source,html]
----
<table class="tableblock frame-topbot grid-all pricing">
<colgroup>
<col style="width: 100%;">
</colgroup>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Standard</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">1 Database</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">5GB Storage</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">20 Users</p></td>
</tr>
</tbody>
</table>
----
You can then use CSS to style that using my custom stylesheet or styles add via a docinfo file.
Cheers,
-Dan