Gosh, I managed to double click on the show history tags column one time viewing a file that has gazillion tags. That stretched the tags column out of its capacity. There seems to be no way at least in UI to get that back to normal size so I can see the columns to the right of the tags column. I searched around and finally found a way to fix that without having to create a new workspace.
To Fix It:
starting from your workspaces folder, where “ProjectName” is the workspace you are having problems with.
\Workspaces\ProjectName\.metadata\.plugins\org.eclipse.team. cvs.ui\
open dialog_settings.xml
search for
"org.eclipse.team.internal.ccvs.ui.CVSHistoryTableProvider"
there is a tag in this section called “COL_TAGS.” That is the size of the tags column in the history view.
Pure-Essence.Net 
Thanks for this post! Very useful for people like me who is experiencing the same problem =)
Thanks a ton that saved me from creating a brand new workspace 🙂