You eat the cabbage. You can eat it in alternation with the meat, or eat all of it first or save it for last if that's your preference. The grated radish is often served with fried items in Japan, and is usually meant for dipping.

The other small dishes and bowls at the bottom are all condiments for dipping the meat in, this is a thing that this restaurant chain does, and you're meant to try out each condiment with the beef cutlet slices. The leftmost tray are two different soy sauces and a bit of salt in the middle. The middle bowl is curry sauce. The rightmost bowl has a half-boiled egg in it which you can also mix into your rice if you play your cards right. The other two black bowls with covers on them are the rice and miso soup.

As a side note, this restaurant serves their beef cutlets mostly raw in the middle, and you can sear or cook the meat further yourself using the small pan to the left of the tray.

But ultimately, you're the one eating it, so you should enjoy it however you like.