All file based data sources can handle the following file types:
CSV, JSON, XML, XLS, XLSX and XLSM.
There are a many file based data sources including Box, Dropbox, Amazon S3, File Upload, Custom REST API, etc. Note that there are file size limits (you can't upload a 317GB file for example 😬 )
In addition, the Custom REST API can handle JSON, XML, CSV. Custom Rest can't handle Excel files getting returned by an API at this time.
If you have any questions, chat in, we would love to help.