After instantiating many game objects, RAM usage rises as expected, but it doesn't drop to the previous level after exiting play mode.

Reproduction steps:
1. Open the attached project
2. Open task manager
3. Look at RAM consumed by Unity
4. Press play in Unity
5. Wait until game objects are loaded
6. Exit play mode
7. Look at RAM consumed by Unity in Task manager

Expected: RAM consumed before and after entering play mode is similar
Actual: RAM consumed after exiting play mode is far more than before entering play mode

Not reproduced on:
Reproduced on: 5.4.4f1, 5.5.3f1, 5.6.0f3, 2017.1.0a6

Results are much worse on Unity 2017. On 5.6 it at least somewhat drops after exiting play mode, but on 2017 RAM usage doesn't drop much after exiting play mode.