Who is Ken Carver from What's Eating Gilbert Grape? and what is their importance?

Ken Carver is Endora's local insurance man..... he is, in fact, the town's only insurance man. Ken is married to Betty Carver and having an affair with his secretary, Melanie. When he dies from what is reputed to be a heart attack, many people suspect foul play, believing that Betty killed him for the insurance money.