Is it bad to eat more than two vitamins a day?

Assuming you are referring to typical multivitamins, they have large safety margins, so taking two doses, even over a long period of time, is not going to hurt anyone. On the other hand, it's not likely to give you any particular benefit, so it's wasteful and expensive, as any excess of most vitamins will simply be excreted. There are a few vitamins, particularly D3, which many people actually need in larger doses than they are getting, but doubling up on a multivitamin mixture is not a good way to accomplish that.