It's like marble, but less natural. Stains, etches, and acquires patina rapidly.

We have a concrete sink as the main sink in our kitchen, as well as concrete countertops in a powder room and bathroom.

The sink is difficult to keep clean. Our housekeeper spends a lengthy amount of time 3x a week to keep it looking very nice and new. However, it is treated like a sink, i.e. not babied, dirty dishes are left in it, etc. It gets spots and looks messy, but scrubbing is able to get it looking mostly good again. I would think that if you are just eating in the area and are reasonable about wiping up spills and avoiding leaving a mess on the table, it would be OK. But it is not a low-maintenance choice.

We also have a marble sink in our kitchen that we virtually never use. That has managed to get more stains/ etches that have been impossible for the housekeeper to remove/eliminate. So, I would have to say the concrete is easier to care for than marble.

You can do really beautiful and creative things with concrete in a wide variety of colors, so I would say go for it if you don't mind a little extra care.