Indeed it would be nice if we could just drop-down an xls file as data stream!

However, there is already a way to use Excel files. You can connect to Excel files using database inputs and calling ODBC. You can then setup an ODBC connection that will point to an Excel file, and connect to that ODBC datasource. You'll be able to use the Excel file as the data this way. It's not as convenient as just dropping a CSV in a folder input, but it will work fine.