Strangers wake up on desert island. Each has a trunk with personal belongings. One has cigarettes in his. Have no memory of what happened before or why/how they had a trunk. Had to learn to live together successfully. Vaguely recall it was some sort of experiment, maybe alien. Published in 60s/70s?
I think it must be
Transit by Edmund Cooper
You have solved a mystery of over thirty years duration! Thank you very much Sabine. I am very grateful.