I am using the Bulk Export to Snowflake action and I noticed that when it runs it appends to my snowflake table. Is there an option to overwrite it?
Yes, you can use the "Trim table" command of the "Database command" action to delete all rows in the target table before exporting new data into it.
Note, however, that having two separate actions to overwrite a table may not be safe - if you already trimmed a table, but your export fails for some reason (e.g., the internet connection breaks), then you may lose your data (until you fix the problem that caused the export to fail and re-run it).
A safer option could be to try to preserve the table until export is finished. For instance, you can export into a temporary table, and then use the "Custom SQL" command of the "Database command" action to drop the permanent table and rename the temporary table to make it the permanent table.
Or let "Bulk export" append rows, and then delete the old rows using the "last updated" timestamp field in a filter.
Experienced Snowflake admins can probably suggest a few other options how to make replacing rows in a table in a safe atomic way.