No need to upload it to Steam. Keep it around and make sure you know which Steam release the .pdb file belongs to!
This is always created when a crash happens. It contains the call stack. The callstack+dmengine.pdb allows us to get a better understanding of what’s going on.
You are already reading the _crash file somewhere right? Google Analytics for Defold reads it at least: GitHub - britzl/defold-googleanalytics: Google Analytics implementation for the Defold game engine