Try something like this. Making the lists scroll and a proper way to terminate the worker thread(s) is something gor you to read up on.

use strict;
use Tk;
use Threads;
use Thread::Queue;

sub create_tk_window {
    my $mw=MainWindow->new (
        -background=>'#dedede',
        -foreground=>'yellow',
        -title=>"FingerLick"
    );
    $mw->geometry("802x618");
    $mw->minsize(802,618);
    $mw->maxsize(802,618);

    my $sent_recvd_listbox=$mw->Listbox (
        -height=>10,
        -width=>60,
        -background=>'black',
        -foreground=>'yellow'
    )->pack(-side=>'bottom',-anchor=>'s',-pady=>2);

    my $server_list_listbox=$mw->Scrolled (
        "Listbox",
        -height=>20,
        -width=>60,
        -background=>'white',
        -foreground=>'black',
        -scrollbars=>'se',
    )->pack();
    return( $mw, $sent_recvd_listbox, $server_list_listbox );
}

sub update_thread {
    my( $Qservers, $Qxmit ) = @_;
    while(1) {
        $Qservers->enqueue( "Server" . int rand 1000 ) if rand() < .1;
        $Qxmit->enqueue( "Sent: la la la " . int rand 1000 ) if rand()
+ < .1;
        $Qxmit->enqueue( "Recv: do be do be do " . int rand 1000 ) if 
+rand() < .1;
        select undef, undef, undef, 0.1;
    }
}

my $Qservers = new Thread::Queue;
my $Qxmit    = new Thread::Queue;
my( $mw, $srl, $slb ) = create_tk_window();

sub updateScreen {
    $slb->insert( 'end',  $Qservers->dequeue ) if $Qservers->pending; 
+   
    $srl->insert( 'end',  $Qxmit->dequeue )    if $Qxmit->pending;    
}

threads->new( \&update_thread, $Qservers, $Qxmit )->detach;

$mw->repeat( 100, \&updateScreen );
$mw->MainLoop;
[download]