Tablet Stands for Bed
Holding a tablet above your face gets heavy in about four minutes, and propping it on your chest puts your neck at the wrong angle for an hour. These take the weight instead.
Cushion stands sit on the lap or the mattress and hold the device at a fixed angle, which suits sitting up in bed. Long arm clamps mount to the frame and swing the screen over you, which is the one that works lying flat. Dual tray versions carry a tablet and a phone at once. Check the clamp width against your device if it is in a thick case.
To support your back while you use one, see reading pillows. More bedside kit in sleep accessories.