If you have a 2E cargo rack in a size 4 slot, you can buy a 4E cargo rack to replace the 2E cargo rack in that slot - providing greater cargo carrying space.
It seems my 1I planetary approach suite only occupies 1/8th of the available room in its slot. I can't find a way to move this planetary approach suite to a smaller slot so that I can take advantage of the size 8 slot for something bigger (more cargo etc)
I thought the big number at left is the size of a slot in which you can outfit various modules. I thought the solid dots underneath corresponds to the space actually filled by the current module and open dots (circles) indicate unused space in the slot.
Have I misunderstood how the size of modules relates to the size of internal ship slots?