People were seated for the speeches and first dances and then the staff gave every on an individual plate of salad, which was greens, strawberries, and maybe pecans and some sort of cheese? There was also bread on the table. Then these plates and the bread were all cleared and nothing was served for quite a bit of time (not sure how much time passed because I left at 8:30 and no one was being served any additional food.)
That would be a big surprise for British guests. This side of the Pond, you don't call people to sit at table (for any kind of dinner, not just weddings) till you're ready to serve the meal. At most there will be a brief few words of welcome and perhaps a grace before the starters are served. Nor have I ever heard of a break for dancing between courses! At most I have known, not at weddings but at other kinds of sit-down dinner, a break of maybe 10 minutes filled by a cabaret turn or a short talk (e.g. at a Trafalgar Night dinner we got a brief talk about the battle between each course). At mainstream British weddings - I can't answer for conservative Jewish or ethnic-minority weddings) speeches and toasts come after dinner, and dancing starts after that.
Re: the bolded --
Does that hold true if the guests have just been eating lots of appetizers during a cocktail hour, too? Or is a cocktail hour with heavy apps not a thing there?
Jem didn't tell us what kinds of appetizers were served during the cocktail hour or how long it lasted. In my community, there is so much food during the cocktail hour, you can definitely be stuffed before you even get to the tables. And multiply that by 20 for a Long Island or Israeli wedding -- the food is so big during the cocktail hour it would be a LOT even for the main meal. Like, maybe, a prime rib station, a sushi station, passed items like potato pancakes, crudite, lamb chops, fruit, little soup cups, and on and on. People don't hold back! That's why I asked Jem if she noticed people eating a lot during the cocktail hour; if this schedule is typical in that community, they would know that it would be a while until substantial food is served. I usually fill up on the appetizers, because they are my favorite part anyway.
Often, in my community, the first course, if it is salad, is already on the tables when we enter the dining room. If not, it is usually served pretty soon, certainly much faster than at the wedding Jem attended. I wonder if the size of the crowd made a difference in how fast the kitchen and servers were able to get all the tables served; I'm guessing, from there being two full tables of one of the bride's parent's work colleagues, that it was a very big wedding. (Or maybe the hora just went on so long because the crowd was into it, and the coordinator didn't predict that and for some reason had told the servers not to put salad out until they finished, which turned out to be a bad idea.) Did I guess right about the size, Jem?