Why do they do this? Because they are cats!
Cats like to be up high. They are drawn to counters, shelves, and tables because it puts them up higher than they are when on the floor.
Also...if you are leaving food on the counter, they jump up because they can get something tasty to eat. Pretty smart, huh?
If you want them to stay off the counter, do not leave food up there. Also, you can cover a towel or a piece of cardboard with double-sided tape and put the towel or board (with the tape side up) on the counter. Cats do not like sticky stuff, so after landing on the tape a couple of times, the cats will learn to stay off the counter.
P.S. Chances are good that the other cats also jump on the counter but are smart enough to jump down before you catch them!