esto hace lo qeu buscas
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<%
counter=0
Do While Not Rs.EOF
%>
<td><%=Rs("NombreCampo")%></td>
<%
counter=counter+1
If counter Mod 3=0 Then Response.Write "</tr><tr>"
Rs.MoveNext
Loop
%>
</tr>
</table>