I see a tendency of my Sim to sit where other Sims are. So if someone is doing their homework in their room and no other Sim is around, the eating Sims tends to go upstairs, sit on the bed and eat in the same room as the Sim doing homework.
So could it be a social aspect for you as well or is that also random ?
It does tend to happen when I eat a meal, I think it also occurs with the Serums and the drinks too as the Sim sometimes doesn't drink the Serum on the spot when told to drink it. It's very noticeable if you have your Sims do daily tasks (e.g., Programming on Computer) where the Sim would likely eat their meals by sitting close to another Sim. The only way to prevent this is lock out the Sim so the Sim won't try to walk in that Room to eat their meals.
It could be a problem on Public Venues since they usually have Sims on the lot, it's likely the Sim would try to eat their meals by being close to another Sim if no Sims are next to the eater. I think you have to bring a meal you prepared especially the meals that don't spoil due to Fresh Chef. Since I don't usually go to public venues and eat, I haven't tried this. I suppose it also could happen with the drinks you ordered from a Mixologist NPC.
It could be a problem with people familiar with the previous Sims games as Sims in the older games usually eat the table or island counters. I know TS4's behavior is part of the multitasking. From this thread, some Simmers say this could happen if a Sim was sleeping that another Sim could eat their meals next to a sleeping Sim although I never had a situation where my Sims would be eating and sleeping.
I just had this in my game. Two of my Sim were sleeping and the third one went all the way upstairs to eat next to their bed. It's a bit creepy.
I would not classify this as a bug per se but I do think it's something that needs tweaking.
Going to add this with a feedback tag to see what other users have to say
EDIT: Added
I have this issue all the time as I often have 8 sims in the household, all with different schedules. Sims will frequently go eat on the double bed of a sleeping sim upstairs instead of eating at the counters with bar stools in the kitchen downstairs or at the dining table downstairs. They actually never use the dining table unless someone is doing their homework there.
I have definitely noticed that sims seem to prioritize being close to other sims above all else in my game. I'd rather they use what was closer or directly chosen - I seem to have a related issue with computers where they won't use computers that I directly commanded them to use (e.g., I want my writer to use the computer in the room with Inspired decor). They seem to prioritize using computers that are closer to other sims or themselves.
