I don't think you would want to rename them. Cakewalk keeps a reference to these files for use in the DAW. If you rename them in the folder Cakewalk will not be able to find them. Anytime you split, bounce, record etc. Cakewalk keeps track of these file for its use and may create new ones. The files in the audio directory are how Cakewalk manages them for its use. They are not meant to be directly accessed by a user. If you want your own copy of wave files for your tracks then you could export them as stems and save them in a folder of your choosing.