Hi.
Thank you for reporting this issue.
A very temporary solution for you to export from python console is:
- open the peakTable on a new module.
 - right click on the header name, copy Gid to clipboard.
 - open the python console, run:
 
  tableModule = ui.getByGid('MO:Peak Table') #the gid can be different for you
  tableModule.tableWidget._dataFrameObject.dataFrame.to_csv('yourFullPath.csv')
Will profile asap to find the memory leak!
Thanks