This option mimics the physical controls on a tape player. This is necessary to load software into certain computer system. As you can see, there are all the standard buttons found on a tape player and the tape images will work exacly as they did on the real hardware.
There are also a couple of keyboard shortcuts that you can use to manage tapes without opening this screen. "F2" will start the tape player and "Shift + F2" will stop it. If you are running a system that has control of the keyboard then you will need to press the "Scroll Lock" key to enable the UI keys for Mame before using these shortcuts.