a simple example, using two counters. One to keep track of the image array index, and one to keep track of the number of colums:

#!/usr/bin/perl

use warnings;
use strict;

my @images;

for (1 .. 20) { push @images, "image$_.gif";}

my $x_wide = 6; # user supplied value

my $output = "<table>\n";
my $i = 0;
while ($i < scalar @images) {
    $output .= "<tr>\n";
    for (my $j=0; $j<$x_wide; $j++) {
        if ($images[$i]) {
              $output .= "\t<td><img src='$images[$i]' ....></td>\n";
            $i++;
        }
     }
     $output .= "</tr>\n";
}
$output .= "</table>";


print $output;
[download]

produces a simple:

<table>
<tr>
    <td><img src='image1.gif' ....></td>
    <td><img src='image2.gif' ....></td>
    <td><img src='image3.gif' ....></td>
    <td><img src='image4.gif' ....></td>
    <td><img src='image5.gif' ....></td>
    <td><img src='image6.gif' ....></td>
</tr>
<tr>
    <td><img src='image7.gif' ....></td>
    <td><img src='image8.gif' ....></td>
    <td><img src='image9.gif' ....></td>
    <td><img src='image10.gif' ....></td>
    <td><img src='image11.gif' ....></td>
    <td><img src='image12.gif' ....></td>
</tr>
<tr>
    <td><img src='image13.gif' ....></td>
    <td><img src='image14.gif' ....></td>
    <td><img src='image15.gif' ....></td>
    <td><img src='image16.gif' ....></td>
    <td><img src='image17.gif' ....></td>
    <td><img src='image18.gif' ....></td>
</tr>
<tr>
    <td><img src='image19.gif' ....></td>
    <td><img src='image20.gif' ....></td>
</tr>
</table>
[download]