Ooooh a party sounds good!
I think i'm gonna take keane trick or treating this year, i think he will enjoy it!
As for the party, sandwiches, mini sausage rolls, mini hotdogs with cheese on cocktail sticks, buns, cakes, crisps, pizza, salad, pasta.
I got the asda magazine today and theres a few things in there with the halloween theme, might be useful for you!