This is actually when I do outdoor time. I grab my video baby monitor and take the older ones out to play.
Activity ideas/games: Help prepare afternoon snack, I Spy (mine love the game as well as the I Spy books), put together my big bucket of car tracks, Mr. Potato Head, big floor puzzles, Kinex building pieces, treasure hunt (I hide laminated shapes, or animals, or whatever in the room for them to find), mine all love books (I often put a basket of books down and they will sit and look at them all).