QTableWidget along with QStackedWidget

[toutarrive]

You are using a wrong and far too complicated approach. No need to use slot to add widgets to your app.
Read Qt doc and go through examples to get a good grasp about layouts and creating widgets.
Once more, for learning purpose, implement your design trough Qt designer and view the code generated.
It will gives you the rigth way to create widgets within a form.

Besides, visit this link (http://www.qtcentre.org/misc.php?do=bbcode) about posting rules.