While you can use separate files for each, you do not need to. You can import from eachexcel file into each table. To manually import the data, you need to go to a layout based on the target table (the table to receive the imported information), before you select Import Records from the File menu. Once you can manually import the data, you can use a script to automate the process.
That was exactly what I needed to do. I wasn't selecting the proper layout prior to import...Thank you!