Uploaded, Package and Version are the upload date, package names and versions of packages for which Haddock generation has never been attempted for the latest version.
The Previous ... columns indicate the latest version of the package for which Haddock generation has been attempted or for which docs were uploaded by the user.
If the Previous ... columns are all dashes it means that no docs exist for any version of the package.

To get an explanation of what the data in each row means, click on the number in the # column for a row.