To get your bedside table height just right, aim for the top of the surface to...

https://brooksfznx367.theburnward.com/the-definitive-guide-to-nightstand-height-for-storage-platform-beds

To get your bedside table height just right, aim for the top of the surface to sit roughly 5-10 cm below your mattress top. This keeps your phone or book within easy reach without feeling like you are climbing up or down to grab them