The location is for the temporary decrypted copies of the files. They will either be cleaned automatically at the earliest opportunity, or when you click the red clean “broom” icon in AxCrypt.
AxCrypt works by decrypting files temporarily and then launching the appropriate application for the decrypted file, which thus is entirely unaware of AxCrypt. AxCrypt monitors the system for the launched app to exit, and when it detects this it will re-encrypt the file and wipe (overwrite) the decrypted file and then delete it.
The public key is, well… public. So it’s no secret. It, and other configuration information is stored in some files in that location as well. None of the other information stored there is secret or sensitive in the sense that all that is in those files is apparent in the local system anyway, such as paths to recently used encrypted files. That information is used to populate the recent files list for example, and to keep track of files in need of re-encryption.
So, if you just let AxCrypt “do it’s thing”, the files you are seeing will be cleaned up when you’re done with them. Of course, do ensure you’re using the latest version of AxCrypt. We’re continually improving it, which includes optimizing such things as re-encryption.