O inserisci il form dentro un td
<table id="tableForm1"><tr><td><form name="form1" id="form1" etc...>qui volendo puoi metterci tabelle div etc....</form></td></tr></table>
oppure usi un div per "simulare" la riga
<div id="riga1"><form name="form1" id="form1" etc...>
<table id="tableForm1"><tr><td></td></tr></table>
</form></div>