okay, habe alles :
for ($z=1; $z <= 10; $z++) {
$last_ten_query = mysql_query('SELECT a, b, c FROM kassa ORDER BY timestamp DESC LIMIT '.$z.',1');
$last_ten = mysql_fetch_assoc($last_ten_query);
echo "<tr>
<td>".$last_ten[a]."</td>
<td>".$last_ten[b]."</td>
<td>".$last_ten[c]."</td>
</tr>";
}