Table etiquette is a very complicated thing especially in such a country like Japan where, I must say, there is food worship. But do not be afraid because Japanese behavior at the table is not as complicated as it may seem at first glance. Japanese rules of conduct at the table have significantly changed for the last one hundred and fifty years. And it surely can be asserted that not any Japanese could behave in accordance with all Japanese traditions. But if you stick to simple rules described below Japanese will treat you more benevolently.
If you happen to attend a classic meal at a traditional Japanese restaurant, be sure you will have to sit on a tatami at a low table. Japanese usually sit in a manner which is called seiza – the traditional formal way of sitting in Japan when your kneels are on the floor, legs are folded under thighs and buttocks are rested on the heels while the back is upright. Such pose is typical for official receptions or solemn ceremonies.
There is another pose called agura – sitting with one's legs crossed (agura literally means foreign or barbarian sitting). It is freer and more informal than seiza. Agura is used only when being among friends, colleagues or relatives. Women are prohibited to sit in such a way. The only thing a woman (foreign not Japanese) can allow in seiza is to slip her legs slightly aside. Japanese understand perfectly well the fact that sitting in seiza is ordeal for a foreigner especially within long period of time. That is why they may allow you to switch to more convenient pose or offer you something like a bolster or a small bench.
As a rule Japanese cuisine is characterized by multiplicity of dishes, snacks etc. At the same time portions are relatively small and served to each person on a tray. An ordinary dinner includes from four to six dishes: rice, miso soup, a few snacks. Dining at official receptions and solemn ceremonies may include up to ten dishes, rice, two soups, deserts and tea.
I hope you know that Japanese use chopsticks (which they call hashi)? During banquets Japanese put hashi onto a special chopstick rest called hashioki. Hashioki is set right from the dishes. Let's itemize the main principles of what one should not do with the hashi.
Mayoibashi (dancing chopsticks) – it is not allowed to draw with hashi on the table and use them like pointers.
Saguribashi (fumbling chopsticks) – if you took a piece of dish it is not allowed to put it back and try to take another one.
At Japanese restaurants they offer warm moist towel – oshibori which is used to clean one's face and hands before dining. The analogue of the phrase "Bon appetite!” sounds like "Itadakimas!” in Japanese and when this phase is pronounced everyone who is present at the table put their hands together and make a small bow. When the meal is finished Japanese say "Gochiso-sama des!” – "Thanks for great food” and slightly bow again.
The main rules while being at the meal table are as follows: a host or a person who have invited you usually begins dining, first dishes which are served are soup and rice, then they propose the first toast finished by the word "Kampai!”. Do not pour alcoholic beverages yourself because those sitting next to you must keep an eye on your glass not being empty. In other respects you can eat all you want and in any order.