Sure, e.g., :
$i = 0;
while($row = mysql_fetch_array($result))
{
if($i ==3)
{
echo "</tr><tr>";
$i = 0;
}
echo "<td>$row['somecol']</tr>";
$i++;
}
Make sure you play a bit with ending your table properly, e.g., doa loop to spit out the last </td></tr> set