Midbreak snack ideas please

[Holidaysarecoming]

I'm having a party for 5 hours (yes I am that mad) for 16 6/7 year olds.

An hour after they arrive they are having lunch. This will be done in prepacked boxes of:

1 Ham (nice if I must - it's a party can I do non-nice ham?) sandwich
1 Cheese sandwich
Handful of grapes
Handful of cherry tomatoes
Pot of jelly
Handful of chocolate fingers

I'm thinking after running around for a couple of hours, 2 hours after this they are going to want something more to eat. Because we are out and about, I want to make up individual snack bags.

Any ideas what I can put in the snack bag, other than a slice of birthday cake, which will be cut up after blowing the candles at lunch time?

TIA

16? 16!!!

Cheese and crackers maybe?

FIVE hours!

erm, should you check on the invites there are no veggies? snacks could include maybe small piece of fruit such as satsuma or small apple, babybel cheese, fromage frais (might need plastic spoon), mini peperami in packet, some of the above?