Tableau Public can connect to Microsoft Excel, Microsoft Access, and text files. It has a limit of 1 million rows of data that is allowed in any single connection. Tableau Public automatically imports that data which is then used for all the analysis. Each account holder will be able to save up to 1 gigabyte (GB) of content to Tableau Public.
The 1 GB of space limit applies at the organization level. If you are publishing as an individual on your own blog or website, you've got 1 GB of space. If you and several colleagues at a company or institution (like a government agency) are publishing data for your organization, then all the data published by you and your colleagues together count toward the 1 GB limit.