In the "Game Modules Generated Scripts" folder, you may find the ObjectReference object. This is created automatically and holds references to objects in your project being used in the Dictionaries, which can't generally be serialized.
Expanding the data, you will notice a whole lot of GUIDs. These are GUIDs that are currently being referenced in some Dictionaries object in your scene.
This data is generated automatically, and should not be modified by mortal humans.