Please don't use Gtk for new code. It is unmaintained, has never been complete, and binds a library that is obsolete. Have a look at Gtk2 instead.

What you're trying to do is quite simple with Gtk2::Ex::Simple::List.

my $slist = Gtk2::Ex::Simple::List->new (
    'Setting'       => 'bool',
    'Configuration' => 'int',
    'Name'          => 'text',
    'Description'   => 'text',
);

@{$slist->{data}} = (
    [ 0,   1, 'Configuration 1',       'Description' ],
    [ 0,   2, 'Another Configuration', 'Another Description' ],
    [ 0, 102, 'Third configuration',   'Third description' ],
);
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Makeshifts last the longest.