Ecco qui...

codice:
<?php

$col=2;
 //metti il numero di colonne desiderate


$arr = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13);
if (count($arr) > 0) {
	$j = 0;
echo '<table align="center" border="0" cellpadding="0" cellspacing="0">';
	while ($j < count($arr)) {
	  if (($j%$col)==0) echo '<tr>';
		echo '<td>'.$arr[$j].'</td>';
	   if (($j%$col)==($col-1)) echo '</tr>';
		$j++;
	}
	echo '</table>';
}
?>
Ciao,
Alessandro