Whether you are eating in a restaurant or at someone’s house table manners are the usual, formal European ones. You will be expected to remain standing until the hostess or host invites you to sit down and only begin eating when they have wished you “bom apetite”.
Most foods are eaten with knives and forks and spoons – including cheese and fruit – and there will be special utensils for fish dishes. It is impolite to rest your elbows on the table and you should keep your hands visible at all times.
Do not put your napkin on your lap; keep it to the left of your plate while eating.
To show that you would like more food, or have not finished eating, place the fork on your plate diagonally from the left with your knife perpendicularly to form a triangle shape. When you have finished eating: place the knife and fork, tines up, parallel with each other on the plate with the handles pointing right; and move your napkin to the right of the plate.
No matter how delicious the food is it is polite to always leave a little bit of food on your plate when you are done.
source