$mine = array();

for ($i = 0; $i < 6; $i++) {
for ($j = 0; $j < 6; $j++) {
    $mine[$i][$j] = rand(0, 100);
}
}

for ($row = 0; $row < 6; $row++) {
echo "<ul>";
for ($col = 0; $col < 6; $col++) {
    echo $mine[$row][$col];
    echo " ";
}
echo "</ul>";
}