DS1 is 3.1 and DS2 is 16mo - DS1 is no trouble at all to occupy while I cook dinner - toys, TV, colouring, etc, etc. "Can I watch big steam engines, please, Mummy?" Yep, course you can, then dinner is a doddle.
DS2...just bothers and pesters and shoves DS1 then wails when DS1 gets (understandably!) cross with him.