I’m new to morph.io so forgive the newbie question, but what is the best way to clean out or truncate my data table between runs?
Welcome @loren 
It’s probably a good idea to try and keep your data between runs as it could come in handy. Adding dates to records is a good way to track changes to data over time. Here’s an example from some scraper training we’ve done: https://morph.io/morph-test-scrapers/fire_danger_ratings_and_total_fire_bans_tutorial
If you really want to delete stuff from your database, and you’re using the scraperwiki library, you can use ScraperWiki.sqliteexecute to run any SQL, including DELETE or DROP, against your database. e.g. to clean out your entire data table:
ScraperWiki.sqliteexecute("DROP TABLE data")