Option to cache datasets in memory, especially in Power Query mode

The example I have is I'm working with a ~300MB CSV file. Every time I make any transforms on the file in Power Query, it goes and fully retrieves the CSV, performs the transform, then dumps it out again. Needless to say this gets really tedious in development mode. It would be nice to be able to cache a dataset in memory, sacrificing real-time access to the data for performance while in Power Query (and perhaps Power View as well.)