Hi Lionel! Welcome.
Where did you get that program?
If you click on "Help" at the top of the screen, does it give you a tutorial or manual?
If not (and sometimes there is little actual help) if you see a menu with "About" on it after clicking "Help", click on that, and it should name the program and authors. We can probably go from there.
ps. it looks like on that screen you push either the CW or CCW buttons to jog your table. A division of 90 degrees would mean your table would take 4 presses of one of the buttons to turn completely around one revolution (360 degrees). You choose which way it turns by which button you press.
The number you enter looks to be the number of steps your motor needs to yield the size of the jog you want.
Since a stepper motor takes many steps to go one revolution, and a worm gear (if you have one in your table) also affects how many steps are needed, the number you need for a certain jog size will be specific to your table.
In the setup you have showing, the number of steps (73) yields a jog size of 4.932 degrees. Each time you press the CW button, your table should jog 4.932 degrees in the clockwise direction. Each time you press the CCW button, it should jog 4.932 degrees in the counter clockwise direction.