To get your bedside table height just right, aim for the top of the surface to...

https://wiki-byte.win/index.php/The_Perfect_Bedside_Table_Height_for_a_58_cm_Platform_Bed:_A_Professional_Guide

To get your bedside table height just right, aim for the top of the surface to sit roughly 5-10 cm below your mattress-top. This makes reaching for your phone or a glass of water feel natural while you are in bed