First, you can choose to pack a meal and eat in the dormitory. If you really can't find a place, the easiest way is to pack a meal and go back to the dormitory for dinner. Generally speaking, the canteen has a package service. If you can't find a place to eat, you can pack food directly.
Second, you can take meals to other canteens. Usually, university canteens are divided into many floors. So, if you can't find a seat on a certain floor, you can take the food upstairs or downstairs to eat. There will be many canteens in a building. You can take your meals to other canteens.
Third, you can go to the canteen more often, because the location is very mobile and there will be vacancies from time to time. In fact, even during rush hours, empty seats are not difficult to find. This is because there are too many people eating, and empty seats may appear at any time. So, you can go to the canteen more often, and I believe you can find an empty place to eat soon.
Anyway, I personally think it's better to avoid the rush hour and go to the cafeteria to eat. During the peak period, we not only have to spend more time waiting in line for meals, but also worry about whether we can't find an empty place to eat. what do you think?