I second the idea of individual portions - either in a lunch bag or on a paper plate. Much better than having a free for all at the table. Also 5 year olds at a party, they will eat but they won't eat much! So a sandwich, or chips and sausage - treat and drink and crisps - plenty !
I have also given up on things like fruit kebabs etc they end up all over the place and hardly eaten.
Paper plate/ cups and table cloth - all can be rolled up and thrown in recycle at end of party !
Birthday cake often doesn't get eaten - so divide portions wrap in foil and send home for party bag
Don't serve grapes (choking hazard) and if you do cut them length ways
Always have a large jug of water available for those that want while the party games are ongoing.
Hide or don't display the food until you re ready to serve it, unless you want half of it eaten before it s time and the party participants crowding around the table instead of the activities. Have a jug of water. / juice for the kids that are 'starving ' or 'need food now not later ' - don't start giving one or two little bits as invariably they ll all want some.
Also check re allergies / vegetarian it s good to have a few extra or plain version for the kids that 'don't like cheese in my sandwich' etc (or be practical and whip out the cheese as say there you go now 
)
I would also go with plain stuff for this age group - salted crisps / popcorn rather than flavoured etc as invariably someone won't eat the flavour you have or they all want the same.
Don't offer too much choice i guess (drink flavour / sandwich filling etc) as you can bet your bottom dollar that they will all suddenly want what you don't have much of lol!
(I speak from 9 years and 3 kids of hosting many parties of this nature )
They love visuals at this (and any) age!
We iced buns with coloured icing and stuck a lolly pop in the top, and put jelly tots on the icing - they all thought they were the best thing ever ! It was meant to look like a flower end result didn't really but kids loved it!
Cutting the sandwiches into shapes with cookie cutters also makes them more fun.
Another tip was I had every child's name printed twice on a sheet of stickers - when they arrived I got each child to find their name and stick it on their coat, and one to wear for the party.
I always have a few extra printed sheets of colouring paper/ word searches / dot to dot puzzles (various sky landers, princesses, my little pony, ninja turtles Lego movie scenes are all available free to print ) and a big box of crayons I have these set up in a corner for the kiddos that don't want to participate or want to have some time out (there s always one or two at a big party)