large assets in 'Resources' folder loading on Editor startup?

We have some fairly large assets in the 'Resources' folder, and we do this so we can load them on-demand in our open world game (even better with Resources.LoadAsync now!). However, it seems like when we start up the Editor, it's loading all of them. This causes Editor startup to be quite slow, and also more memory use. I can see that the meshes/textures by using the memory profiler, and when I do "find references in scene", nothing comes up. So I assume this is because the editor is loading 'Resources' on start-up. Is there a way to avoid this?

Thanks.