The information on this page is confirmed up to POSper revision 423
Generator tables edit
These tables are simply storehouses for the next available id for other tables that they serve.
Restaurant specific tables edit
These tables seem fairly specific to a restaurant setting rather than being generally applicable to any POS.
These tables are spatial by nature
Ticket handling edit
These tables deal with handling tickets
User management edit
These tables manage users including user rights
The rest edit
The rest of the tables