The most important table etiquette in Japan is saying traditional phrases before and after a meal. Japanese people say, "Itadaki-masu" before a meal and say "Gochisou-sama" after a meal. These phrases mean thanks for the food and also indicate the beginning and the ending of a meal. If you are eating with Japanese people, try to say these phrases.
Japanese people use knives, forks, and spoons to eat certain dishes; however, chopsticks are the most frequently used utensils. Try to hold the top chopstick between the thumb and the middle and index fingers as you hold a pen and hold the bottom one between the thumb and the ring finger. Then, move the top one to pick up food.
One of chopsticks etiquettes is not to directly pass food from your chopsticks to somebody else's chopsticks or vice versa. It's also important not to stick chopsticks vertially into food, especially into a bowl of rice. It's not polite to wave your chopsticks above food dishes or to use your chopsticks to point at somebody.
It is polite to lift small bowls of rice or soup when you eat. It prevents you from dropping food. When you do not get a soup spoon, it is proper to sip the soup out of the bowl and eat the solid food with chopsticks.
It is common in Japan to make some slurping noises while eating noodles, such as ramen, soba, and so on. People say it tastes better if they make slurping noises.