In ArcGIS Pro 2.9, the following functionality was added:
What's new in ArcGIS Pro 2.9
You can now save a stand-alone table as a layer file (*.lyrx).
Idea:
Could the layer file documentation be updated to reflect that change? Right now, the docs don't seem to mention that .LYRX files support standalone tables:
ArcGIS Pro - Save a layer file
A layer can exist outside of your map or project as a layer file (.lyrx). This allows others to access the layers you've built. You can share layers over the network or by email.
That would help avoid confusion for users.
Related: Idea - Layer/table definition files (readable in a text editor)