I agree with Alaska Man that things may depend on settings and, as a general rule, you'd better know what you are doing.
That said, I regularly delete this folder (on Windows) without ill effects. (I also set a fairly low cache limit). Once I process my RAWs, I rarely return to them, so there is little point keeping the cached copies.
If you are not sure, ...
It depends on how you have set the preferences in your particular system.
We do not know how you have set the preference for what is stored in that folder.
Is it all the metadata for all your raw files?
I do not know enough about what the default settings would be to advise you. But i do know enough to not delete things until i understand them. (learned the ...