For the most comfortable setup, aim for your bedside table to sit roughly 5-10...

https://victor-wiki.win/index.php/The_Golden_Rule:_What_Does_%225-10_cm_Below_the_Mattress%22_Actually_Mean%3F

For the most comfortable setup, aim for your bedside table to sit roughly 5-10 cm below the top of your mattress. This makes it effortless to grab your phone or a glass of water without straining your arm