The golden rule for bedside tables is comfort and reach. Aim for a height that...

https://www.unitedbookmarkings.win/in-my-experience-the-golden-rule-is-to-keep-your-bedside-table-5-to-10-cm

The golden rule for bedside tables is comfort and reach. Aim for a height that sits between 5 to 10 centimetres below your mattress top. This keeps your phone or book within easy reach without you having to stretch or strain