Hi Aditya,
You can use DbCleaner to clean your personal when it is full, usually the platform notifies you by email when the limit is exceeded, be aware of this so you don't have your personal deactivated for exceeding the limit, whenever you delete any module or app, try to make a backup before, but try to make Kilian's suggestion before cleaning your personal with dbcleaner, another suggestion would be for you to create an action to export the table data to excel, that way you could import them later, which may be something simpler for you.
Regards