H.M.
I'd say that most 10 and 11 year olds will entertain themselves by bringing their own games, toys, etc.. And, if it's family, it's been my experience, growing up in a very large family, that the old kids like to help entertain the younger ones, especially, when you're talking just an hour or so.
Why not have some younger games/activities and enlisting the older kids to help. Provide them a bit of incentive by giving them a helper gift of something you know they like. Indoor bowling is cool, if you have the room and a set. Pinatas are always a good time.
What about Twister. Yeah, you modify it a bit, but they like to play with the circles and moving the body around.
I think the video in the background is a personal choice. I hate television for my child, but have also allowed her to watch a video once in awhile and know I will eat my words on what i will or will not do. If it makes for a nice time, then do what works for you!
Good luck.