I designed this bracket/holder to place tablet in when not in use, the bracket  goes between the matress and base and is held in by friction, can be charged while in the holder, thus no need for space on the bed side table. Parts are printed separately and pushed into each other, friction alone keeps it in well. Also has holes where you can put and melt some filament in to keep the 2 parts secured. Support needed for part 1 only

The size is designed to fit a 10.4inch Teclast tablet with cover

I printed in petg but any filament will probably work.