apart from your original list I woudl only add:

dips and things to dip in them
biscuits in the shape of a 2
birthday cake

I buy top quality sausages, cook and chop up into bite size.

Depending on age of children I think its good to cut the triangles again so you get mini triangles (if you get me) and saves waste.

Dont over cater, I find they only pick.

I always hold back the sweet stuff until the savoury has been served.

My son loves olives and feta cheese - but not sure if many children do. Top tip - use the canned ones in brine. soak in water, drain and sprinkle with olive oil - saves a fortune on the fresh.

Pizza
Garlic breads
CHocolate fingers
Mini doughnuts
Grapes
Carrot sticks that have bit boiled for 3 mins
little potatos
bread sticks
baby tomatos

Definietly ice cream ith chice of sprinkles...

from all the parties dd's been to i'd say pizza and garlic bread go down best. better than sandwiches. also those awful little cocktail sausages. they always get scoffed. then jelly and ice cream with choice of sprinkles/sauce.

selection of sandwiches
tomatoes and carrot sticks
few crisps
hotdog sausages
pizza
chiken nuggets
various cakes mini ones mouth size
bowls of fruit, chopped up
juice not fizzy
jelly and ice cream
birthday cake

what a great feast

I thought fairy cakes was enough for the sweet stuff but maybe I should add more

variety of fresh fruit and raisins - should be OK even for fussy eaters

ice cream and jelly

obviously the food wasn't mixed in one bowl but each could choose their own topping

I did Large bowl of pasta, with a bolognaise sauce, cheese, chopped up sausages, tomato sauce and let them help themselves.
Caters for all and works out quite cheap.

I have found that buffets are useless with kids as they pile up their plates and hardly eat a thing