The answer is maybe with a side of nope. Joking aside I would never advise someone to delete data without knowing what it is. PPKG files are used to deploy both apps and configuration data, so you could technically delete with out any problems up front. If said packages is part of your system manufacturers recovery process you will break said process.
I would instead start by clearing out all temp locations, if hibernate is enable disable it it will save you space equal to the amount of system ram you have. You can also shrink Windows recovery snapshots to safe many GBs and/or run a tool such as
TreeSize Free | JAM Software to locate areas of cleanup. You can also reset the update base which will remove all update rollbacks...