We have had several examples through the thread of differing ways of eating according to country or culture or type of food, so I do think some of the particularities of British table manners might be a little out- dated in a multi-cultural society.
Personally I use just a fork to eat quite a few meals especially rice-based ones, though it would not be my habit to hold the bowl close to my face and shovel food in, as I have seen the staff in Chinese restaurants do. In some Asian cultures food is eaten without cutlery. In France children are taught to put their hands on the table as fists, when not actually eating.
But I think it is important that children are brought up to behave in public and in other people’s homes or at a formal dinner. If they are not taught at home, they will embarrass themselves later.( Mind you, we have seen appalling behaviour from public school students yet they must know what is expected at their formal dinners).
So my minimum would be, wait until everyone is served unless told otherwise, don’t eat with your mouth open, don’t talk with your mouthful, and try to conform with the cultural norms of the people you are eating with( as far as is reasonable). Be neat and tidy with cutlery. Don’t cough all over everyone, don’t complain, be polite. No mobile phones. Make conversation, include the children. Stay seated until everyone leaves the table or ask to be excused.