How does Mesh.CreateVBO work?

I am trying to fix some performance issues in our game and I came across huge spikes caused by Mesh.CreateVBO. What I do know is that this function is called each time I modify the vertices of a mesh, which I do frequently. However most of the time the execution time for this function is 7ms (in Editor) and probably even more on Android, which is the target device.

Now it looks like this phenomenon is somehow related to the number of meshes in my game, but it's not a linear rise as I'd have expected. It seems that once I reached a certain point (around 90 meshes) it goes haywire.

I also noticed a frequent rise of the mesh count. While my actual count is about 80 approx. every second there is a spike where the count seems to double for the duration of two frames. After that it goes back to 80. And exactly on those frames where the count goes back to normal I get the vbo spikes.

Does anyone have a solution for this, or can at least shed some light on when CreateVBO is an expensive operation and when not?

EDIT: It looks like at least the mesh count spikes exist only in editor. Im not sure if the CreateVBO spikes go away with them as well.