This thread is old, but...
I have used a modified HList I found on CPAN called Tk::HListplus that worked quite well for this problem.,
It uses (as an example):

$widget->header('create', 0, -itemtype => 'resizebutton', -text => 'Pa
+th');
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It allows you to double click on a header to make the column about 1 character wide (so you can grow it again) and also permits the mouse to grab the right side of the header box to adjust the column width.
I also don't see a problem with initally having the column the correct size for the contents. I use:

$widget->columnwidth($column_number,'');
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to make it automatic.
I would recommend using:

    $widget = $host_box->Scrolled(qw/HListplus
        -scrollbars osoe/);
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so that you have enough room regardless of the host_box size.
(1st post)