I think you may be mixed up on the tar commands, I work from FreeBSD so perhaps you have a different version of tar
This will just create a container for the "files" and they will be the same size as before, but with the benefits of being one file, name.tar
tar -cvvf name.tar files
To create a compressed archive
The extension is debatable - tar.gz but .tgz is shorter
tar -zcvvf name.tgz files
To extract the compressed archive
Note, some file formats are not worth compressing using the above methods, typical examples include media files such as video and music. From my experience they tend to grow in size by a few mb.
[root@sites /tmp/test]# fetch "http://www.wordlistgenerator.net/results.aspx?regular=1®ularish=1&irregular=1&select=randomly"
results.aspx?regular=1®ularish=1&irregular=100% of 865 kB 4104 kBps
[root@sites /tmp/test]# mv results.aspx\?regular\=1\®ularish\=1\&irregular\=1\&select\=randomly test.file
[root@sites /tmp/test]# du -h test.file
[root@sites /tmp/test]# tar -cf test.tar test.file
[root@sites /tmp/test]# du -h test.tar
[root@sites /tmp/test]# tar -zcf test.tgz test.file
[root@sites /tmp/test]# du -h test.tgz