Mapping a csv field to Meta Title and Meta Description using feeds and metatag
You could create fields for the metadata, hide them in "Manage display" and map them to the Metatag module (add the field tokens as content), as I described in the answer to "How can to make required the fields keywords and description of the metatags module?".

Now in your CSV import you add the metadata to your manually created fields, and the Metatag module will fetch the content.