Thanks for sharing the project!
I can not reproduce your issue. The memory consumption looks stable:
Start RSS = 37232
End RSS = 39064
Start RSS = 39064
End RSS = 39064
Start RSS = 39064
End RSS = 39064
Start RSS = 39064
End RSS = 39064
Start RSS = 39064
End RSS = 39064
What version of VTK are you using?