M.S.
I would probably just do sandwiches/fruit/chips/yogurt. Very simple. Me and my 3 year old have "picnics" sometimes inside our house - we put a blanket out in the living room and sit on the floor to eat. He helps me in the kitchen and we put all our food in a basket to bring it to the living room. Pretty funny really - he is only 3 and thinks its so cool :)