Yoast SEO is a fantastic plugin that makes writing title and meta tags a whole lot easier.  The only problem is that you can only import and export general settings.  If you happen to install a fresh install of WordPress and import posts, that SEO data remains blank.  This little plugin is a a quick and easy lifesaver to save you hours of data entry work, especially for large sites with lots of pages.  You can check it out here:  https://github.com/wp-plugins/yoast-csv-importerexporter