I was watching "Teacher Comes to Dinner" last weekend and I got to thinking about how many times we see the little back porch/barbecue/dining area of the Cleaver home, with the nice double doors leading into the living room. Besides that episode, I can remember one early one where Larry visits and they have a cookout, and in Uncle Billy's second episode they also eat on the porch. I think in the White Fox episode, we see Ward and Wally talking in that area (Ward is cleaning up, I believe). In "Beaver's Tree" we also briefly see the porch area as Beaver and Wally try to transplant the tree.

Can anyone think of any other instances?

It is a very nice porch/dining area for eating al fresco.

There are a couple of episodes, or maybe just one, where they are painting porch furniture out there. There is one that opens with Ward working on something out there, maybe the door, and Wally enters. I don't remember exactly what they talk about, but it kind of sets things up for the next scene. That first scene is routinely cut out.

I just remembered one where Ward is painting the furniture, and Beaver is later stung by a bee that got stuck in the wet paint. It's the one where Beaver is giving June the silent treatment.