For the best reach and comfort, your bedside table should sit level with the...

https://mike-wiki.win/index.php/What_is_the_Average_Bedside_Table_Height_in_the_UK%3F_A_Professional_Guide

For the best reach and comfort, your bedside table should sit level with the top of your mattress or up to 10 cm below it. Most UK beds work perfectly with a table between 55 and 70 cm high