There are couple ways to handle this.
Since your files are so well named, I'd suggest the following.
Select the files.
Right-Click on them, then from the menu choose Library Tools -> Fill Properties from Filenames
You can let JRiver try an automatic setup, or fill in your file naming template if that doesn't work.
It looks like you can use the template [Artist] - [Album] - [Track #] - [Name] for manual setup. It's one of the preset options.
Let me know if you need more detailed instructions.