When I wrote this, I had totally forgotten that I occasionally use Tk::GridColumns. This is a moduke of its own, not included in the main Tk module. Here is a simple example, which shows your environment variables example data:

#!/usr/bin/env perl
use strict;
use warnings;

use Tk;
use Tk::GridColumns;

my $mw = Tk::MainWindow->new(-title => 'ENV');
my $gc = $mw->GridColumns(
#    -data    => [map {[$_, $ENV{$_}]} keys %ENV],
    -data => [['cherry', 'red fruit'], ['carrot', 'orange vegetable']]
+,
    -columns => [{-text => 'Name'}, {-text => 'Value'} ],
    -colattr  => {-anchor => 'w'},
    -itemattr => {-anchor => 'w'},
)->pack(
    -fill => 'both',
    -expand => 1,
);
$mw->MainLoop;
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BTW Tk::GridColumns can also become sortable, scrollable and editable, see EXAMPLES