I usually learn something from your code so I tend to read it carefully. I noticed that the join() inside the map() is only joining one item so there won't be a '='. When I run your example the third column is blank. The split /=/, $pair; section is only populating $name. I was able to fix it by placing a second int rand 100 inside the join().
After a few more tweaks I ended up with this:
#!/usr/bin/perl
use warnings;
use strict;
use Tk;
use Tk::Pane;
my $mw = 'MainWindow'->new;
my @array = map join('=', $_, int rand 100, int rand 100), 1 .. 100;
my $top = $mw->Scrolled('Frame', -scrollbars => 'e')->pack;
for my $pair (@array) {
my ($x, $name, $value) = split /=/, $pair;
print "pair=$pair, name=$name, value=$value\n";
my $frame = $top->Frame->pack;
my $label_index = $frame->Label(-text => $x,
-width => 10,
-relief => 'groove')
->pack(-side => 'left');
my $label_name = $frame->Label(-text => $name,
-width => 30,
-relief => 'groove')
->pack(-side => 'left');
my $label_value = $frame->Label(-text => $value,
-width => 25,
-relief => 'groove')
->pack(-side => 'left');
my $label_description = $frame->Entry(-text =>'description',
-width => 30,
-relief =>'groove')
->pack(-side=>'left');
}
MainLoop();