As many Steam community members have noticed, the size of the initial pre-load for Mortal Kombat X is about 3 GB. This is because we are using a new feature of Steam that allows the game to be played while the full download is streamed and installed in the background.
As soon as the game is played for the first time, a batch of DLC content will appear in your download queue. Check the Steam client to see the download progress on DLC items labeled Mortal Kombat X Install Pack 01 through 23.
You’ll be able to play the game while these downloads complete.