For more possibilities in outputting aligned text, explore man page for printf some more
[tt]
printf "%-30.30s %9s %9s\n" FileSystem SIZE FREE
printf "%-30.30s %7.2fGB %7.2fGB\n" /1st/file/system 12.5 1.23
printf "%-30.30s %7.2fGB %7.2fGB\n" /2nd/file/system 4 0.66
printf "%-30.30s %7.2fGB %7.2fGB\n" /3rd/file/system 5.8 1.01
[/tt]
Mostly this needs some trial and error, but it is much easier than tabs as you're not limited to fixed tab stops...
HTH,
p5wizard