The golden rule for bedside tables is comfort and accessibility. Aim for a...

https://lilyluxemaids.com/the-golden-ratio-of-bedside-comfort-matching-your-mattress-to-a-60-63-cm-nightstand/

The golden rule for bedside tables is comfort and accessibility. Aim for a height that sits between 5 and 10 centimetres below the top of your mattress. Most UK beds work best with tables in the 55 to 70 centimetre range