Jason the commenter

Okay, so I can actually explain this. It's not what you think at all. It's a silent battle between the conflicting goals of directors, set dressers, screen writers and actors, and the cost benefits of set dressing and redressing, that eventually settled on a weird convention where no one really eats in movies or TV shows. First, no director likes an empty table at a meal. It looks dull, and lacks vital interest. So the director tells the set dresser, make it look good! So the set dresser piles on food and other things to fill up the empty space, often far more than would be rational at a regular meal because film is a visual medium and it's easier to make something look good with MORE than less, BUT, it's not actually made to be eaten. It's gotta last for several takes, which could take HOURS to film, so some of it isn't even actual real food, just props, and the stuff that is real food, is cold, congealed (and not really sanitary or safe to eat after hours under hot lamps) and it's also covered in more carnuba wax than than you can find at a car detailer. It's only made to look good on camera, and only a little of it is actually designed to be eaten by the actors, but here's the thing, even that small part has gotta look good too. So what is stable, safe and doesn't need a lot of maintainance to look good on camera? You got it...TOAST. Toast is dry, can last for hours without much hassle, it doesn't go off, etc., so it's usually the part of the meal on set that someone can actually eat. Either that or something like crackers or breadsticks. If it's mass-produced crackers, all the better because it's easier to match shot after shot. Now enter the actors. They have to sit around all this food, that is made to look good, but is actually fake, cold or gross, and they have to do many, MANY takes, but here's the thing. If you actually go at with full gusto like a regular meal, you'll end up eating several meals worth of food, which is very hard to do. Also, actors tend to be particular about what they eat and no sane person wants to eat cold, congealed food covered in carnuba wax for hours on end anyway. So they pretend to eat or only nibble on the safe things to eat, which is most often again, something like toast. Oh! And I didn't even mention the continuity problems! If you are filming something over hours and the actors are eating your props, they destroy your food/props in the process, which means if you DON'T get the take, you have to reset the food and REMAKE the food to match what was on screen before and it's a total nightmare. So again, you need a food that's easy to copy and replicate so you can reset for the next shot quickly and once again, TOAST fits the bill. It's quick, cheap, easy and all toast looks the same. Same for crackers, etc. Seriously, once you know this, you'll never see toast in films quite the same way. It's incredibly ubiquitous in films. Now enter the screen writers. You have to write a scene at a meal, that allows people to talk, without actually eating all that much, because that would get in the way of the dialogue and would force you to redress and reset the table and food after every take anyway, which costs time and money. You have a table FULL of food that no one can or wants to eat. How on EARTH can you make that make sense?! Well, the easy thing is, you interrupt the meal. You have something come up, a fight, someone tosses a drink at someone and storms out, or they are running late and have to go and can't eat, or something else, doesn't matter, just give the actors a reason not to eat and save everyone from the director and the set dresser the hassle. So no one actually eats a meal in the movies except maybe some nibble on some crackers and toast. Seriously, actors go hours and hours filling up on stale toast and bread, it's boring and not very tasty, but at least it's safe and sanitary. The director gets a set that is dressed nicely, the set dressers have food and props they don't have to reset too often, actors don't have to eat too much, and the shot goes through and everyone is happy! Except the audience who thinks, why didn't they eat the food? It's so funny how all the behind-the-scenes logistics and drama is the actual source for so many of the tropes we see in TV and film.