That would mean exactly that, yes - there is a bird on the table and while it's there, it's jumping.
And yes, it's a useful distinction.
Similarly with a bird flying over a table - if it "flugas super la tablon", then it starts at one end of the room, flies over the table, and ends up at the other end of the toom, while if it "flugas super la tablo", then it flies around (in circles?) above the table; it is over the table the whole time rather than only during part of the motion.
I can think of a lot of situations where the "flugas super la tablo" vs. "flugas super la tablon." For instance: La blua birdo flugis super la kampo. As opposed to: La blua birdo flugis super la kampon. One being a blue bird flying around and around over a field, the other being a blue bird that just shoots by. We have a lot of bats where I live and they do tend to fly around and around over things. It seems, in general, that the -n ending means the action is completed or the object is traversed, whereas the -o ending might mean the action is sort of ongoing. There must be a lot of variation depending on the verb and the preposition.
It shouldn't be, in my opinion, because that would mean that the bird, already on the table, starts jumping. "Sur la tablon" means "On to the table" (or "onto the table")
Many English speakers don't distinguish between "on" and "onto.".
Here's a random example.
Clearly the problem is with the dog moving from being not on the table to a location that is on the table. For sure the owner would not be happy with the dog standing on the table without jumping. The approach of the course authors seems to be not to frustrate learners by making them learn the difference between "on" and "onto" in English - especially if it's optional in many regions.
Because that would mean the bird was already on the table when it started jumping. For that meaning, in Esperanto, you would say, "La birdo saltis sur la tablo."