You can pause any active download from the Mac App Store by right-clicking on the apps icon in the Dock and selecting “Pause” from the menu.

Resuming the download is just a matter of right-clicking again and selecting Unpause.

I have not used this for a while, so do not know if it still works.

What it does works is in App Store, you can Pause it there.

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/tlTOt.jpg