Airtable email automations do not support user-defined tables.
A very hacky workaround would be to have a utility table to store the data. The new table would have one for each field of data you want to display, and another identifying field. Have your script create new records in your utility table and set the identifying field to the same unique identifier for all of the records. Output that unique identifier. Then perform a "Find Records" action that finds the records in the utility table based on the unique identifier. Include the results of the "Find Records" action in your email as a grid. Then have another script that deletes the records created by the first script.
Another alternative would be to use a third party email service that supports full html. Your script could then output an html table.