FME:
*Europeans have fork in left hand and knife in right.
*Americans (no idea if just US or a Western Hemisphere wide thing) will switch.
However, Euros will have a fork in their left hand if eating with a fork alone while Middle Easterners and South Asians will eat with their right if fork alone.
Remove our shoes when entering the house.
In the US I notice (and am annoyed by) people in restaurants being in a hurry to place their order, eat, pay, and leave. Once they finish eating they look around anxiously for their check.
In the Caribbean (and according to my gf, much of Europe) meals are enjoyed in a much more leisurely manner. In the Caribbean especially, a server brings your check only when you go out of your way to request it.
My impression is that in America, dinner is just the beginning of an evening, whereas in some other places it is your evening.
The bolded part is what I have trouble understanding. I first read about this in a book on British ways of doing things, and had trouble believing it then.
WHY try to place food on the rounded back of the fork (if it’s tines down, then the concave part is facing downwards)? It’s guaranteed to fall off unless you do something odd – holding it on with your knife, as well, or having the fork tines jammed into something to keep things from rolling off the unstable convex upwards surface of the fork. To me (raised in a place where everyone does this) the 'natural" thing to do is to hoist your peas or cubed carrots or whatever so that it’s cradled in the concave-upwards “bowl” of the fork. but I think if I was raised without utensils and given a fork, this is what I would have done right off the bat – food doesn’t fall off the fork if you do it that way. Putting things on the rounded back of the fork means it’s likely to fall off, so why do it?
(Pronging meat or anything the fork is jabbed into is different – I can see using the fork tines down, in that case, because friction will generally keep the item in place. But your creamed corn isn’t going to want to stay on a fork held that way.)
The book I read mandated pronging several peas onto the tines of the fork, then using your knife to mash others onto the back of the fork, where friction with the tines they’ve been squeezed between and the retaining power of the peas pronged on the tines keeps the others in place.
But it would be simpler to simply scoop them up with the concave part of the fork. No pronging or mashing required.
The reason you do this, the book claimed, is that the polite fiction is that you are there to converse with your hosts – eating is incidental to your interaction, so you do what you can to slow the process down and have more time to talk.
Corroboration:
Ahhh, yes, the after dinner drinks sipped while enjoying the live music. Then moving from the table to the bar for a few more drinks while the band starts their third set. Then dancing.
I think it’s because it’s cumbersome and undignified to switch your grip on the fork. You have to have the tines pointing down so you can skewer the meat and cut it with the fork. And the fork in this orientation works well enough for everything else. It’s not as cumbersome as you imagine. I don’t think I ever skewer beans or peas - they stay on the back of the fork just fine. It does slow you down, because you can’t fit as much food on the back side, but that’s a good thing.
You don’t place it on the fork, you stab it with the fork. If it’s the kind of food that can’t be stabbed, that’s why spoons exist. If no spoon is available, that’s why Real Bread With A Decent Crust exists (in those countries in which it does): to keep the stuff in place.
There are times I want to eat and get out of there, and times I’m happy to linger. I expect the server to know the difference 
In NYC, by the way, I always have to make a scene to get the damn check. The server literally disappears after the last food is served, never to appear again.
So if you have mashed potatoes, you put down the knife and fork, and then pick up a spoon to eat a bite of potatoes?
I go to restaurants to eat, not to relax. Home is for relaxing. You eat, and then you go home. What’s so hard to understand about that?
I think elsewhere, they expect the customer to know which restaurants to go to if they just want to eat and get out, and which restaurants are for spending a whole evening.
Well, I presume you dine out for the pleasure of it, rather than mere fuel? Otherwise you might as well sit in your car eating a burger.
If for pleasure, then isn’t ambience, good conversation, a leisurely glass of wine part of it?
Really? Of all my friends and relatives (probably 30 people or so), only 2 wear shoes in their house. Yes, I am American and so are all the people referenced above. (NV, UT, WA, IL, TX, MI, PA, GA)
In some places, restaurants are for special occasions. If you just want to eat, you eat at home, or you eat at a casual eatery/cafe.
There’s possibly a misconception about knives & forks here. In Britain & Ireland the table is set with a fork at the left and a knife at the right. As a lefty this suits me. However many if not most people are right handed and will swap the cuttlery round. Why tables are set for the lefty minority is beyond my ken.
I prefer to relax wherever I am. Pouring the last glass of wine from the bottle, I’m thinking about what wine we should order as our second bottle. And I’m in full-out relaxation mode.
As my cites show, some people do indeed insist that items be placed on the back of the fork, not merely transfixed by it.
Ah, another thread where the SD Cultural Elite Society tell us uncouth Americans why we aren’t doing it right. Whatever “it” may be that day.
Never mind that we’ve been doing it “that way” forever, and it works fine.
Beyond that, what’s wrong with Tuesday night dinner being a “special occasion” just because?