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Linux does have the concept of a RAM DRIVE (multiple concepts actually, including ramfs and tmpfs being common).   You should look at https://en.wikipedia.org/wiki/Zram - ZRAM claims to be exactly what you are looking for - ie a compressed block device in RAM.

That said, You may be "doing it wrong".

Linux makes strong use of pipes - so if I have an uncompressed file and I want to compress it and ship it to another system - which sounds like what you want - I would use pipes to do it.

Assuming you can SSH into the target machine you can do something like -
 
      tar -czf - /path/to/files/to/compress | ssh user@target "cat > file.tgz"

The above will tar the appropriate files, pipe them to the remote system and dump it in a file called file.tgz.     The "-" in the tar command means write to stdout which is then piped to ssh and dumped on the remote system.

There are lots of options and variants to the above.  You could, for example, use zcat instead of tar to stream a single file, and you could also automatically extract the file on the remote side by replacing the cat command with something to extract the tgz file.