<form action="" method="GET">
    <input type="text" name="x" placeholder="ilosc kolumn">
    <input type="text" name="y" placeholder="ilosc wierszy">
    <input type="submit" value="Generuj">
</form>
<?php

$tabx = (isset($_GET['x']) && (int)$_GET['x'] ) ? (int)$_GET['x'] : 6;
$taby = (isset($_GET['y']) && (int)$_GET['y'] ) ? (int)$_GET['y'] : 6;


function print_tab($tab) {

    foreach ($tab as $trow) {
        foreach ($trow as $tcell) {
            echo '<div style="width:65px;text-align:center;margin:0px;padding:14px 3px;float:left;border:1px solid #ddd;">';
                echo $tcell;
            echo '</div>';
        }
        echo '<div style="clear:both"></div>';
    }
    echo "<br>";
    echo "<br>";

}

function generate_tab($x,$y){

    $top = true;
    $right = true;

    $array = array();
    $up = true;
    $right = true;
    $val = 1;

    $cursor_x = -1;
    $cursor_y = 0;
    $half =false;
    $count = $x * $y;
    while ($count>0) {

        if ($cursor_x == $x-1 && $cursor_y == 0) {
            $up = !$up;
            $right = !$right;
            $cursor_x++;
            $half = true;
        }

        $cursor_y += $up ? -1 : 1;
        $cursor_x += $right ? 1 : -1;


        if ($cursor_y < 0) {
            $cursor_y++;
            $up = !$up;
            $right = !$right;
        }
        if ($cursor_x < 0) {
            $cursor_x++;
            $up = !$up;
            $right = !$right;
        }
        if ($cursor_y >= $y) {
            $cursor_y--;
            $up = !$up;
            $right = !$right;

            if ($half) {
                $cursor_x++;
                $cursor_x++;
            }
        }
        if ($cursor_x >= $x) {
            $cursor_x--;
            $up = !$up;
            $right = !$right;
            if ($half) {
                $cursor_y++;
                $cursor_y++;
            }
        }
        if (!isset($array[$cursor_y][$cursor_x])) {
        $array[$cursor_y][$cursor_x] = $val;

        } else {
        $array[$cursor_y][$cursor_x] .= ' '.$val;
        }



        $val++;
        $count--;
    }


    return $array;
}

$tab = generate_tab($tabx,$taby);

print_tab($tab);