Retrieving List Contents and Metadata

What is the best way to retrieve the list contents and the list metadata (list label, internal name, type etc.) via a workflow? I know we can query both individually - nms:group has the list metadata and wen can simply do a Read List to read the list contents. How to append the List metadata to the contents - without manually adding a join key? For instance, if I am reading 5 lists, I don’t want to manually enter a segment code or introduce a manual join key.