The cardinal dining crime is eating noisily; nothing is more
likely to get you noticed and promptly blacklisted. Keeping your
mouth closed while chewing and taking care not to overfill it will
enable you to breathe steadily. Eat at a relaxed pace and really
think about your food. Not only does this make you appreciate
what's on your plate, but it can also help you moderate your intake
if you are so inclined. Wolfing down course after course will make
you appear greedy.
Talking while there is food in your mouth should be avoided at all costs - even when you have a conversational gem up your sleeve. Try to avoid directing a question at someone who is in the mid-mouthful, but don't despair if you mis-time. A smile and an understanding nod will encourage them to swallow without rushing, spluttering or making sheepish gestures.
In Britain the knife should be held firmly in your right hand, with the handle tucked into your palm, your thumb down one side of the handle and your index finger along the top (but never touching the top of the blade). It should never be eaten off or held like a pencil.
When used with a knife or spoon, the fork should be held in the left hand, in much the same way as the knife, with the prongs facing downwards. On its own, it is held in the right hand, with the prongs facing upwards, resting on the fingers and secured with the thumb and index finger.
A spoon is held in the right hand, resting on the fingers and secured with the thumb and index finger. Food should be eaten off the side of the spoon; it should never be used at a right angle to the mouth.
Cutlery should be rested on the plate/bowl between bites, and placed together in the bottom-centre when you are finished.
When dining in a group, always put others' needs before your own. Do your bit in offering communal dishes around the table, and hold them to assist your neighbour.
Wait until everyone is served before you start eating, unless your host/hostess instructs you to start immediately.