If the "View content revisions" permission is enabled, there is currently no means by which to hide the author information. You always get something like "Thu, 2012-01-19 13:53 by firstname.lastname".
If a particular content type has "Display author and date information" turned off (in the content type configuration's Display settings), the author information should not show in this table, only the date. (The dates have to be shown as these are the table IDs for each revision.) So the table display should respect that setting by only showing ""Thu, 2012-01-19 13:53". It currently does not.
There is a movement to split this configuration setting into two. It would make this situation clearer. See the following for details:
Comments
Comment #1
crifi CreditAttribution: crifi commentedThis is a feature request since it works as designed.
Comment #1.0
crifi CreditAttribution: crifi commentedAdded example.
Comment #2
xjm(Merging "node system" and "node.module" components for 8.x; disregard.)