Best way to remove marble tiles?

Can't tell from the photo, but what's that beige edge? MDF or the side of the tile? Either way, it's not marble, just regular ceramic/porcelain.

Crowbar if you want to make minimum mess and hopefully they'll pop off if the installer didn't use great thinset. Otherwise, smash them up with a hammer and clean up the mess.

So actually the beige is all grout. You can see the thickness of the tile at the bottom used as a baseboard. You sure that's not marble?

It's irrelevant whether it's marble or ceramic or porcelain etc.

Smash/pry/pneumatic hammer. No magic to this.