Leftover import fields
 

I did an import a long time ago.
I used Calories Table and Field Comparison Utility to see if I had stray fields in my tables.
It came up with many fields that start with import that claim not to be part of the standard table build.
Should these fields be there?
Can I delete them?

Examples
moderator
importmoderatorid

phrase
importphraseid

pm
importpmid

pmtext
importpmid

poll
importpollid