No, only one copy of the song is saved. The different categories are from ID3 tags, electronic labels in the files, all being read and categorized from the one copy of the song.
But the songs should not be that big. WMP probably also put copies on your computer–you can look in its Settings to see where it’s storing them, find that folder on your computer and see how large the songs are there.
Or you could connect the player, open Windows Explorer (Computer or My Computer) and look at the individual songs. Look for a music folder, or search the unit for .mp3 files or .wma files, and right-click for Properties. Typically an mp3 is about 1MB or 1.5MB per minute of music.
It’s possible that your Windows Media Player was set to rip to .wav instead of .mp3. Those would be much larger files–about 10MB per minute. You should look at Settings in Windows Media Player and choose mp3 at 320 kbps. Then rip again to mp3 and put the smaller files on the player.
But first, take a look at some individual songs, and report back here what you find in Properties. Or you can examine the files with the free program Mediainfo. http://mediaarea.net/en/MediaInfo