How to reproduce:
1. Open the attached project
2. Open Bug scene
-There is this documentations script http://docs.unity3d.com/ScriptReference/Mesh-triangles.html , just expanded to 10000 triangles
3. Open Profiler and Windows Task Manager
4. Play the scene (or build and run it (don't forget to Autoconnect profiler))
5. Check the Memory usage (Simple or Detail) update it after some time and notice that it is increasing quite fast

The same result in Editor and Player
Not reproducible: 5.3.0a4