You should seal marble, but you can't guarantee it won't stain. However, it's not like a white carpet, where you instantly ruin it if you spill. If you left wine or tomato sauce or olive oil sitting for extended periods of time on your marble, you might get discolorations. A bigger risk with marble is etching from acidic substances or scratching. However, that said, marble is used often in kitchens. I like to ask my clients: if in the next 5 years, you got a couple small spots and nick on your marble, would you regret getting it. If you the answer if no, then go for marble. You just need to be a bit more careful with it than granite.

A great way to see how marble would be is to go to a local granite fabricator (installer) and ask for a scrap piece of White Carrara Marble. Take it home and try to ruin it! Put different thing from the kitchen on it, and see what happens. That will give you a realistic idea of what to expect.

Thanks!