legs for this slab that looks like a shamrock.....sort of. I think that the slab would be about two or three inches, it's white pine.
Cut it the length you want the table to stand then carve it out so that you have legs left. Then it would be one piece table and legs.
4 straight pine branches with bark on or peeled off. Tenon cutter dowel ends and pine branch stretchers between the legs. Just my .02. Something like this?
Personally I'd find a pine stump with root flares. Dig around stump with backhoe. Cut as low as possible. Peel bark. Drill stump to accept dowels on top, and slab on bottom to match dowel pattern. Done. Sit it flare side towards the floor.
You can-ish White pine drys really fast. A cookie 3-4 inches thick is going to not only check but slpit, probably into peices. It would need to be treated as soon as it was cut. Over sizing it's thickness would help too. Not just for stability but to give some extra material to mill out flaws/checks.
You can slow it down, but you can't fully stop it. I would like it do what it wants naturally and put in some bow-ties to stabilize it.
Lots of good ideas, I'll have to get a bigger saw ready and then make my mind up what we'll do with it.