I made a drop table for my Saunders enlarger, having a low ceiling in my darkroom for making prints >16x20.
I recommend not mounting to the wall, but to the table itself. The reason is that the wall and table may vibrate at different frequencies. The greater the mass of the table, the less vibration (really the vibration is absorbed). Use birch plywood, and use glue + screws to make it thicker; the plywood having wood laid at opposite angles will help with absorbing vibration. There are several ways to minimize vibration, but they may be overkill. Get a carpenters triangle - make sure everything is 90 degrees, otherwise you have to shim your easel, which is not fun.
Get a cabinet maker to make the table for you if you do not have the tools or know-how, but it may be an opportune time to start collecting tools! Or, find an old wood table and cut out the middle for the drop down! Then you will drawers for storing lenses, dodge/burn tools, or make a paper safe.
Good luck.
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