I don't bleeive you can without the risk of getting rust in your food...
It's best to pour it into a plastic container and cover it with either a lid or some cling film / tin foil
We don't use much can food, but if we do, we always put the remains of it into a dish & put it in the fridge until the next day, then throw it away if we don't use it.
Yes you can. Just cover top of can with foil or cling film and refridgerate. But dont leave it more than a couple of days. Modern food cans don't go rusty in a week in the fridge.