both of our doodles do this. I think it reverts back to having a type of "cave" for them. We actually have dog beds under our formal living room table for the babies!
Brewster loves to lay right next to or under the kitchen table. He usually does this after playing, and I think it's because the laminate is cool on his tummy. I have to watch him, though, or he WILL chew on the legs..... :/