As theDucks says, this plugin does not crash calibre, nor does it gobble memory. It was last updated about a year ago and in that time not one of the tens of thousands of users has had an issue with it, until the two posts of yours and the one above it.
I suspect you have fallen victim to the "random" general crashiness that a minority of users have reported with recent calibre versions. Again not a problem I personally have experienced in the slightest on either my Win 7 64-bit or XP machines. Kovid hasn't been able to track down why it started happening, but there are threads in the main forums about it. Certainly I believe it must be "some other" software component on your machine which is causing the issue, because the 99.9% majority of users don't have a problem. And if it isn't something I can replicate, it certainly isn't something I can do anything about.