If you have your data being displayed rite now in a standard DW repeat region then you should try adding in the repeat selection server behavior for DataAssist. You would want to apply it to the <td></td> portion of the row, then repeat it for how many you would like to see across.
I don't think this is the optimal situation though, I think it would be easier to just create your own display for the records on the page with the repeat table server behavior. It will use the same recordset so the page should look and work about the same except you will have multiple entries for each row. Always make a backup to your existing working page before you try to alter or update it.