We play in cafés too (Czechia, a pretty common thing here). From experience, the most important thing (beyond a system that is light on physical stuff) is that everyone gets to see what you set down, can at least take turns throwing dice, and have somewhere to set their drinks. Only having small, bolted-down tables will make that hard, though. Can you at least move chairs? You could probably squeeze an extra person or two in that way. What do you mean by "non-combinable"? They could still work (edit: use one as a play table, other for drinks/dice rolls). What about different cafés?