Depending on how you go about it, one song can "gobble up" megabytes galore - and maybe even a gig or two. I understand that a wave file uses 10Mb per minute of record time; by contrast, an MP3 file might "burn" 1Mb per minute, depending on the resolution you set (64 byte versus 256 byte) per second. Since we are probably considering a studio setting where we record our songs, we will focus on the .WAV file format.
Since I am more familiar with the Tascam DP24, I'll discuss that a bit. Your three-minute song itself will grab about 30Mb of disk space; but if you have ever looked inside a folder produced by a DP24, especially after you have done several tracks with punch-ins and multiple "takes" on a track or portion thereof, you won't believe at first how many files reside in that folder! AND THEY ARE .WAV FILES! That is why the DP24 has an option to DELETE UNUSED FILES. This option should in most cases not be used until you have the song recorded pretty much to your satisfaction.
I don't know much about all those tracks except that they contain snippets of your song. I have no idea how you would use one of them if you were attempting to "get it back" into your active song. One thing for sure: If you look at that Size parameter on one of your songs done on a DP24, you will probably be surprised at the amount of disk space you have "burned" in that song - at least until you use the option to delete the unused files. I imagine that other recorders burn through the megabytes at a similar rate if they are full-featured recorders. So far as I know, that 10Mb per minute is pretty much a "hard figure" for the .WAV files. I periodically make a backup of the card which I use in the Tascam. Since I do not scroll around through the letters to hammer in a song name because I cannot see the display, I have been letting the DP24 name songs by its naming convention (SonG ABCD) where the letters are digits taken in sequential order. I then keep an index file containing those file names and the real song name associated with each song. Once I have a backup, I can delete some songs from the card to avoid filling it completely. My 16-gig card will hold several songs, but I am carefull to not "push the envelope" because I did that once; when the card became full, the record process stopped, but I didn't know what had gone wrong (I finally noticed with a scanning device that there was a Card Full error showing). The main result of my carelessness in filling the card was that I ruined the song and had to start over after cleaning up the card and freeing several gig of space.