Japan has many table etiquette rules that are very different from European ones.

You can slurp (and you even need to, when eating dishes like soba, udon, ramen - sipping the noodles loudly). In some restaurants, it is said that making sounds while eating is even mandatory. Otherwise it's impolite. The owner may be offended for this and ask the client to leave the establishment without payment (although, knowing the Japanese politeness, this is hard to believe).

You can talk with your mouth full. My Japanese friend could not understand how to chew first before speaking. He says that it doesn't matter, while eating food remains in the mouth.

You can lift the plate/bowl from the table while eating, bring it to your mouth, drink soup (misoshiru, etc.)

One can sit cross-legged at a table, even on a chair.

Rice must be eaten up to the last grain, moreover, using chopsticks for this.

Regarding chopsticks - there are a whole bunch of rules that I will explain later.

The Japanese believe that moving after eating is harmful, it is best to sleep or just lie down. Therefore, they often have dinner very late, closer to bedtime.

Tea is usually poured 2/3 into a small cup. Better a few times than a full one.

Before eating, be sure to say: itadakimasu
During meals: oishi/umai
After meal: gochisosama

What table etiquette surprised you the most in Japan?