Ivan, where exactly are you having a problem?  It sounds like you are already collecting the information about the multiple items in your workflow.  If you are trying to create an excel file with that information you can look at this post for details on how to do that. http://www.vadimtabakman.com/nintex-workflow-list-to-csv-uda.aspx.  If you're having another issue, can you give some more details on where you're having the issue.  Thanks.

Thanks Brendan,

Here is the story:

I am updating user details in SharePoint list, with Active Directory as my source. Usually, most of the items are pretty much updated with the site workflow. But now I would like to see what updates happened during the workflow run. When an item already up to date, then it can be ignored. But if there has been any update on any of the fields of the item, I would like that to be collected, reported in an Excel and mailed.

Hope it is clear now.

Ivan

How about creating a temporary list. As you go through your workflow to see what was updated, add an item to your temporary list and whatever fields you deem necessary. Then use Vadim's site to help put it into an Excel file and send it. You'd basically update Vadim's workflow with your additional actions like emailing.