Put the Table (non-scrolled) into a Scrolled Pane. That will keep things visible. I don't know what your variable cell sizes will do in this setup, you may have to do some fancy callbacks, like reconfiguring the canvases' scrollregions after a mainwindow resize. Anyways..... think Scrolled Pane.

#!/usr/bin/perl -w
use strict;
use warnings;
use Tk;
use Tk::Table;
require Tk::Pane;

my $graph_width=300;
my $graph_height=400;
#my $graph_height=800;

my $title_c;
my $group;
my $canvas;
my $table;
my @group_names=('A','B');
my $col=0;


my $graph_win = MainWindow->new( );

$graph_win->withdraw;

my $pane = $graph_win->Scrolled('Pane')->pack(-expand=>1,-fill=>'both'
+);

$table= $pane->Table(
        -rows => 2,
        -columns => 2,
        -scrollbars => 'e',
        -fixedrows => 1,
        -fixedcolumns => 0
        )->pack(
        -expand => 1,
        -fill => 'both',
        );


foreach $group (@group_names){
        $title_c=$table->Label(
                -text => $group,
                -relief => 'groove',
                -font   => "{Arial} 15 bold",
                -borderwidth => 2,
                );
        $table->put(0,$col, $title_c);

        $col++;
}

$col=0;
foreach $group (@group_names){
        $canvas = $table->Scrolled("Canvas",
                -scrollbars => 's',
                -width    => 300,
                -height   => $graph_height,
                -background => 'white',
                -borderwidth => 2,
                -relief => 'groove',
                -scrollregion => [0,0,$graph_width,$graph_height]
                );
        $table->put(1,$col++, $canvas);
}
$graph_win->deiconify();
$graph_win->raise();
$graph_win->geometry('600x500+30+30');

MainLoop;
[download]

Thanks,
This was my original implementation but it lacks one important feature of the Table which is keeping the header row visible regardless of the scrolling.
A possible work around is to pack another frame on top of the pane which will hold the headers.
But then it's quite hard to deal with maintaining the widths of the headings and the table cells the same.

I'm not sure what you are trying to do, but maybe you are overcomplicating it by trying to use a Table. This was posted a few months ago by rcseege. Just add some header canvases.

#!/usr/bin/perl
use strict;
use Tk;
use Tk::Pane;

# by rcseege

my $mw = MainWindow->new;

my $sPane = $mw->Scrolled("Pane",
   -scrollbars => 'se',
   -sticky => 'nsew',
   -bg => 'black',
   -width => 300,
   -height => 300
)->pack(qw/-expand 1 -fill both/);
my $container = $sPane->Subwidget('scrolled');

foreach my $row (0 .. 3) {
   foreach my $col (0 .. 3) {
      createTile($container, $row, $col);
   }
}

foreach my $i (0 .. 3) {
   $container->gridRowconfigure($i, -weight => 1);
   $container->gridColumnconfigure($i, -weight => 1);
}

MainLoop;

## Each 'Tile' is a Frame containing a Scrolled Canvas +
## another Frame containing zoom controls.

sub createTile
{
   my ($parent, $x, $y) = @_;

   my $tileColor = "black";
   my $tile = $parent->Frame(-bg => $tileColor)->grid(
     -padx => 5,
     -pady => 5,
     -row => $x, 
     -column => $y, 
     -sticky => 'nsew'
   );

   my $sc = $tile->Scrolled('Canvas',
      -scrollbars => 'osoe',
      -scrollregion => [0, 0, 200, 200],
      -width => 125,
      -height => 125,
      -background => randColor()
   )->pack(qw/-fill both -side top -expand 1/);

   my $count = int(rand(6)) + 2;
   foreach my $i (1 .. $count) {
      my ($x, $y) = (randNumber(), randNumber());
      my $size = randNumber();
      $sc->createRectangle($x, $y, $x+$size, $y+$size,
         -fill => randColor(),
         -outline => 'black',
         -width => 2
      );
   }

   my $bFrame = $tile->Frame(-bg => $tileColor)->pack(qw/-side top/);
   $bFrame->Button(
       -text => " Zoom Out ",
       -command => sub { $sc->scale(qw/all 0 0 .5 .5/); }
   )->pack(qw/-side left -padx 5/);

   $bFrame->Button(
       -text => " Zoom In",
       -command => sub { $sc->scale(qw/all 0 0 2 2/); }
   )->pack(qw/-side right -padx 5/);
}

sub randColor {
   my @colors = qw(red yellow blue orange green purple);
   return $colors[rand($#colors + 1)];
}

sub randNumber {
   my ($max, $min) = (100, 10);
   my $size = int(rand($max));
   $size += $min if $size < $min;
   return $size;
}
[download]

---

I'm not really a human, but I play one on earth. Cogito ergo sum a bum

I agree!

Thanks zentara, I learned something also.