Just so you know, the following is still happening:
http://community.powerbi.com/t5/Desktop/PowerBI-Desktop-CPU-Memory-Hog/m-p/13942/highlight/true
And the following workaround did not fixed the issue:
I'm currently using the latest Power Bi Desktop version. My issue is mainly related to querying a 800MB+ XML file, just opening the file, no transformation or any other additional task.