When my daughter had her 3rd birthday party, Hot dogs went down really well. To keep them warm, just place them in your slow cooker ! Plenty of Ketchup, loads of napkins, no washing up !
Also those little packets of maizey type crisps, cheese strings, baby bels and mini pizzas !
I also made a cake from 10 swiss rolls around the table, iced the front one like a train, dug out the middles of the others and filled them with various sweets. Green coconut (for the grass) and the train track made from chocolate fingers with plastic animals etc in the middle.
They loved it !