For the best look and comfort, aim for your bedside table to sit roughly 5-10...

https://www.mediafire.com/file/ci4j8luw7hfr284/pdf-67918-84454.pdf/file

For the best look and comfort, aim for your bedside table to sit roughly 5-10 cm below the top of your mattress. This keeps your lamp and water within easy reach while you are in bed