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

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 your nightstand surface to sit about 5-10 cm below the top of your mattress. This prevents you from knocking things over while reaching out from bed