If in a temp file, they can be deleted.
I don't know what to delete because all files are weird with random extensions.
If you cannot determine what a file or folder is for through Bing Google, a trick I learned many years ago when wondering if safe to delete an unfamiliar file or folder is to simply rename the file or folder by appending the name with the date and the word "delete", then see if something breaks (get a file not found error). To illustrate:
Old folder name: de34juidfj277eu
New folder name: de34juidfj277eu-3-14-16-delete
Old file name: readmesqlexp2005.htm
New file name: readmesqlexp2005.htm-3-14-16-delete
Then, I just go about my business for the next few days and see if everything is still working. What typically happens for me is I forget about it until weeks or even months later until I stumble on the file or folder again. By appending the folder or file name with the date and the word "delete" I can see how long it has been since I renamed it, and "delete" tells me my intentions. If all has been working since that date, I know it is safe to delete.
If something breaks, since I only "appended" text to the name instead of totally renaming it, I don't have to remember the original name - I can easily see what it was, and simply cut off my appendage. I mean rename it back and be good to go.
Note if one of those odd files names is several gigabytes in size, it most likely is not being used.