What is the optimal size for the AssetBundles loaded into the Webplayer at runtime?

I have to divide the complex environment for loading to the WebPlayer once the user opens it on the webpage.

The idea is just to fill the scene with the loaded assets smoothly.

What optimal sizes for the assetbundle files would you suggest? Is it better to import 100 files 100 kB each or 10 files 1 MB each?

I mean the smaller assets the smoother, but there must be some overhead with any new file, but I have little experience how big that really is.