We had fridge locks at one point. My first daughter would open the refrigerator and just sit in it. We put the lock on the top of the fridge, so she couldn't reach it. We had a different kind of fridge with our second child, so we had to use some sort of clamp or vise thing that my husband picked up at a hardware store.
I remember my sister's kids would do something similar, they just liked to get into the fridge to open stuff and spread it around on the floor. My thoughts at this age are to keep some snacks he can have in reach. I used to keep things in muffin tins on the table, because they might not eat very much, but would come back at various times for another bite. That's if you don't mind grazing, which I didn't. Neither one of my children is a grazer now.
I had cabinet locks on my cabinets, but I kept a few unlocked with plastic bowls and such, so she had something she could get into that wasn't too messy. I don't really have a lot of suggestions if you can't keep him from opening the refrigerator. Maybe hiding the yogurt on the top in the back, so at least that is one messy thing he isn't getting into.