More info on SerializedFile memory entry.

We're looking at splitting our assets up into many bundles to remove duplication, but it appears that as the number of bundles grows the amount of memory used in the SerializedFile increases fairly dramatically. Is there anywhere that has more info about this entry. Is this an overhead per bundle? Is unloading the bundle the only way to free that memory? Any other pertinent info would be appreciated.

Thank you,

 

I also want more information about this. There's way too little documentation on the topic. What are those "buffers" for? Why are they just sitting there?