The instruction cx:tabulate is to be used to generate tables faster than would otherwise be possible. Use cx:tabulate in templates when creating export files or so called mail merge files.
Without cx:tabulate :
<cx:fetch item="u" eospec="$activity.fspec">
<tr>
<td><cx:write value="$u.firstName"/></td>
<td><cx:write value="$u.lastNamePrefix"/></td>
<td><cx:write value="$u.lastName"/></td>
<td><cx:write value="$u.address"/></td>
<!-- ... etc ... -->
</tr>
</cx:fetch>
With cx:tabulate :
<cx:fetch list="users" eospec="$activity.fspec">
<cx:tabulate list="$users" columns="(firstName, lastNamePrefix, lastName, address, ...)" type="html" />
</cx:fetch>
