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

https://www.nav-bookmarks.win/for-the-most-practical-setup-aim-for-your-nightstand-to-sit-between-5-and-10

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