Tray stand assembly
It can be tricky to get the stand together the first time. However, once you get the idea it's easy. First check the orientation of the sides. Bring the sides together rotating the pieces in your hand. Keep the pieces at about 45 degrees to each other and align the notches and slide together. Sometimes it can help to let the bottom touch the floor.
Below is a brief video illustrating how to assemble the two parts of the tray.