I think no need to call catering la, because I think our aim is to let bb(s) play together & momy, daddy chat, chat, chat... so... I suggest to buy some handy food like sandwiches, cakes or even something "ready to eat", plus packing drinks like lemon tea, etc....
because I want to have more time to play & chat, so eating should put less effort (this is my opinion)
About what to do.... Anyone had been to playgroup before ? Can you tell us what will do in playgroup?
I suggest sing some songs, crawling competition (are every babies crawl now ?) any other suggestion ?