Use a very large, very soft light source and place it close to the camera axis. A big softbox directly behind or just above/behind the camera is a good starting point; two softboxes side by side can act like one larger source. Keep the camera parallel to the table and move the camera/table setup until the iPad reflects a blank area of the ceiling or a neutral surface instead of the light itself.

If the softbox appears in the iPad screen, shift the camera or light slightly and test again. A tripod helps because you can fine-tune reflections without changing framing. If needed, crop later rather than forcing a problematic angle.

Your current light is likely too small or too close in a way that still behaves like a point source, causing fast falloff and visible shadows. Increasing the apparent size of the light source will make shadows softer and more even.

For the most shadow-free result, use a light tent/light shed or add more diffused light from multiple directions. Even bouncing a flash off the ceiling can help fill shadows. In general, larger diffusion and more fill light reduce both shadow contrast and uneven lighting.