In general, you can't, they're not designed that way. Once you pack/grid/table your widget, then pack/grid/table is responsible for positioning the widget (managing geometry), just look inside http://cpansearch.perl.org/src/SREZIC/Tk-804.030/Tk/Table.pm

To be able to visually drag widgets about, directly, you need to use Tk::Canvas or Tk::Zinc (see zinc-demos) or Tk::place ( 15-puzzlegame in the widget demo) or Tk::form ( in widget demo, under Tix Widgets, 'form_mgr' => 'The form geometry manager'),

Another option, is to create a ghost-image, a faded copy of the widget, one that isn't managed (pack/grid/table) and drag that around, until you find the final resting place

Hmm, I suppose you could remove the button from the table (like packForget) when you start dragging ... I'll get back to you on this