One of the most misunderstood classic meals, and one that is having a renaissance with steampunks and lovers of the better sides of life.
At it's simplest, afternoon tea involves tea, bread, butter, and a sweet, a pause between the main meal of Dinner and the nighttime Supper menu. This might be simply brown sugar on the bread, to a sweet bread, to a multi-coursed meal with sandwiches, cakes, candy, etc. Those of the German sphere of influence might substitute coffee for tea, and those who are aligned otherwise, that is Spanish, Italian, or French, should make their own decisions, as to follow British traditions, or to follow those of their colonial heritages: to those of the African persuasion, you might want to investigate these...you don't have to be Scarlett O'Hara. Be French! Be British! Be anything but Ulster Scots!
The best afternoon teas have a guest of honor, that is some person who will be King or Queen of the afternoon. They will "pour" that is, they will greet each person, and give to them which beverage they will most enjoy. This is a high privilege, in that you are taking, in some ways, the role of the host, yet, do not have the host's responsibility. Simply stated, if everything goes right, it's the guest of honor's merit, if anything goes wrong, it's to the host to make it right. In practical terms, this is only an issue with a tea of four, or more: to do so with less is simply ridiculous.
One of the most interesting ideas on the tea front is the 'tea banquet', an adaptation of the kaiseki meals connected to the tea ceremony. As defined in Real Simple magazine, the rule is "Herb tea, for one, alone, Green tea, for two or three, Black tea, for four or more!"
Whoever would give a banquet for just one person? Well, that person might be in bed, for one or a dozen reasons (sickness, childbirth, ....), and would like to celebrate with a fairly harmless/possibly beneficial fluid. Also, this is one of the most intimate things you can do for a person...serve them, and not eat yourself. The suggested menu was goat cheese in herbed honey, with toasted homestyle bread, and fruit. Be on hand for conversation, and of course, sharing is optional...
Green tea. Ceremonial, astringent, a dinner tea, no doubt. This is for someone you'd like to honor with the best that you have, or being a singleton, a couple who've always been kind to you. Menu: Chicken teriyaki, green beans, rice (with some tea leaves in it.)
Black tea. Somehow, this recalls the feeling you get from collegiate memoirs of Cambridge or Oxford in the palmy days from 1920-1950. Ale is available, but what people want is tea, by the quart, there's Something Afoot (like the beginning of the Hobbit, a murder mystery, or computing As We Know It), people are drinking and eating and talking at an amazing rate of speed, and what they're eating is egg dishes (like a quiche), tea-dressed greens (green salad with a little tea in the dressing), and a good cheese-with-jam-and-crackers for dessert.