But then when it comes time for the cake, you ask them to not have cake, because the cake is only for certain people. Not a good way to have a party. Feelings would be hurt possibly.
I agree, I do have some trouble with the closed table.
I suppose if you had a branch of the family that was allergic to chocolate or diabetic and couldn't eat cake, that might be more to the point. Because taking Communion when you are not in a state of grace, or when you do not believe in the Real Presence, is actually dangerous to the soul.
Most priests will explain that to the congregation. My daughter and her hubby are both Catholic, but since we were Episcopalian and converted, a ton of our friends and relatives are not Catholic. We also had in attendance everything from Conservative Jews to a Wiccan priestess, not to mention the unchurched.
Nobody was mortally offended at all. And everybody who wanted cake got it. :-)