Ideas to keep young children amused at a family party?

[Africa2go]

Hiring a function room for an afternoon family celebration of about 30/35 people, about 10 of which will be children aged 10 or under. There is some outdoor space where parents can take their children (if weather is fine, might be able to have a couple of outdoor games - think giant Jenga or large Connect 4) but wondering what we can provide if the weather isn't great. Its only 3 hours, will be food at some point so not masses of time, but want to provide something. Thought of colouring books/ puzzles - or even trying to get a magician / someone to tell a story / make balloons but don't really want to go the whole hog with a children's party entertainer type thing (as its not a children's party). Any ideas gratefully received!

Balloons - not modelling just regular. Quite a lot of fun to be had by kids and adults playing keep it off the floor! Likewise bubble machines!

Oh thank you. Hadn't thought of bubbles!

One of those cardboard castles they can colour in?

I would have some stuff to make cards, a couple of child friendly board games, balloons, maybe cupcake or gingerbread decorating and a couple of books as well as colouring stuff.

10 under 10- what ages specifically? The things that would amuse a 2YO are quite different to what a 9YO would like so tailoring an entertainer like a magician might be quite tricky. But little ones always love bubbles and even adults like lawn games like giant Jenga or Connect 4 so those would be good if you can get outside. Colouring is usually appreciated too, you can could get a mix of age appropriate colouring books.

Rent a jump castle, that's always a crowd pleaser.

Card games like Snap, Top Trumps and Dobble
Where’s Wally? books

When we've been to similar events, bubbles, stickers and colouring books have sometimes been provided and are appreciated. What has been even better has been when someone has brought a load of lego or train track or similar which a whole group of kids can play with, whether they know each other or not. Can any of the parents of the children bring something like that?
Also, if there's some outdoor space, some balls or bean bags or something.

Brilliant suggestions, thank you