[Lazarus] vanishing main menu wanted

[duilio foschi]

these images show what I have now:
1.
https://ibb.co/CwKYdvv
the main menu is attached to the form (standard behavior)

2.
https://ibb.co/wghVxrp
when I switch from Tab1 to Tab2, the main menu stays visible

These images show what I would like:
3.
https://ibb.co/TmDdcRB
the menu is attached to Tab1

4.
https://ibb.co/ngL5jnt
when I switch from Tab1 to Tab2, the menu disappears

Which is the best way to get this effect?

Maybe a TFlowPanel with a number of TEdit controls inside?
Maybe a simple TStringgrid?

Any suggestion?

Thank you

Peppe