How to keep a child busy for hours in the summer: DIY: Giant Ice Cube Awesomeness - filled with plastic animals, dinos, and such. And I'm sure you could put in food dye before its frozen to color it like the ice block in the photo.
Table Quidditch can be played as Quidditch Beer pong or as a fun game with kids on a points system. Easy to make and very fun for Harry Potter fans of all ages! Great for Harry Potter Birthday Parties, Showers, etc.