They're pretty good at self entertaining at that age as mainly they just want to run around, make lots of noise and eat junk.
2hrs is the max, after that they're done.
I like to do an over lunch time slot so 11-1 works well, that way you can use some of the time giving them food and they'll be ready to eat it.
Leisure centres sometimes have sports halls they rent out with soft play stuff which are reasonably priced.
Last year for DDs 7th birthday we did a small garden party as we werejust in that inbetween place where groups were allowed but only outside.
We had the big garden games like Jenga set up, a piñata hung from the tree, a big box of brightly coloured chalks and chalk bombs that they throw and it splats on the ground, water pistols, stuff like that. We warned parents in advance to not send the kids in nice clothes and to expect them home tired and grubby.
We had kids music on so they could dance about.
For food we did pizza, chips, some fruit and veg (mainly for show, let's face it kids don't voluntarily pick the veg when there's chips about!). Then for pudding we did make your own sundaes, big tub of Neapolitan icecream and then a selection of sweets, chocolate, marshmallows, sprinkles and sauces.
An hour of running about like crazy things, 20-30 mins to eat, 5 mins for singing and cake then 20-25 minutes for them to finish off playing while we cut the cake and added it to the party bags before parents arrived to pick them up.
Party bags were
- whatever sweets they grabbed from the piñata, a slice of cake, a toy they picked from a bowl (selection of stuff we'd found on sale, in the Works or in a pound shop, no individual item was more than £1, stuff like Lego mini figures, balls, colour your own tote bag...)