There are only a few icons displayed in the upper right corner of the screen. They show, in order: current level (1), amount of experience (2) that you currently have and how much do you need to get a new level, number of available orders to download (3) and amount of money (4).
This menu is used for basic actions that you can do in the workshop: downloading new orders, checking your inventory, using your tablet as a shop (after unlocking this ability), using your notes or saving / loading game. However, when you stand next to a car you can view repairs status for this particular car instead of downloading orders. If you use the icon at the bottom you can move a car around the garage. When you click on parts you can select other additional options from the menu such as diagnosis by using a tool (measurer), mount / dismount mode or examine mode.