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

https://blogfreely.net/rothesqlmw/how-to-choose-the-perfect-nightstand-height-for-reading-in-bed

The golden rule for bedside tables is comfort and accessibility. Aim for a height between 55 cm and 70 cm to match your mattress. For the most natural reach, your table surface should sit about 5 cm to 10 cm below the top of your mattress