I recently used a data recovery software, Minitool Power Data Recovery, to recover my data from a raw partition drive, drive E. Along with my original files, an additional folder is obtained called "Raw Files" which has in itself sub folders named Adobe PDF file, MKV Video, PNG image, etc. I cannot access any PDF or image files in these folders. Some images which are accessible does not seem to belong to my original data and are repeated. Are there things part of my original data which has corrupted?
They are the results of carving. The tool you used most likely performs both directory tree reconstruction and carving as an additional attempt to recover most data. Quoting from this answer of mine:
File carvers → They scan any kind of disk and try to recover known file types by checking for specific signatures. For instance, JPEG files always start with bytes
FF D8. This method only works for non-fragmented files and you don't get any clue about a file's name or location.
Tools that work at the file system level → They read (possibly damaged) partitions by looking at the directory tree and then use the information specified there to access files. For this reason they can access any file as long as it is listed in the file system.
Files that cannot be recovered by the second approach might be recovered by carving, thus the tool performs an additional carving step. Of course the signature matching might (and usually will) fail if the files are fragmented, so you cannot access them because their contents are not retrieved correctly.
Data recovery software rarely discriminates between cached images from your browser and stuff you intended to keep. It can also dredge up old data that has only been deleted, such as when someone sells a computer used and only reformats the drive instead of doing something like running Derek's Boot and Nuke (DBAN) on it. This can be especially disturbing if it's a company which uses refurbished components to build new computers (Compaq right before HP bought them, late model Gateway, eMachine, 90s model Packard-Bell, and a few other no-names), as you can dredge up someone else's data if they got sloppy on the refurb.
When the image files are repeated, these are usually images which have come down from a website, such as an icon, and been left in cache.
In the end, it doesn't matter; if you can't load them on a working computer and open them, they're just useless bits.