When building an Unreal Engine 4 project from the command line the default behavior of RunUAT is to include all Unreal Editor content as well. This bloats packages but is the safest default behavior. I urge you though to build without editor content. This will ensure your packages are smaller and prevent any assets in your game from depending upon editor content by accident.
To build an Unreal Engine 4 project from the command line using RunUAT pass the “-SkipCookingEditorContent” argument in your call to RunUAT.
Example:
RunUAT.bat -SkipCookingEditorContent BuildCookRun -project=PATHTOPROJECT