Tables:
woocommerce_attribute_taxonomies - Table for storing attribute taxonomies - these are user defined
woocommerce_termmeta - Term meta table - sadly WordPress does not have termmeta so we need our own
woocommerce_downloadable_product_permissions - Table for storing user and guest download permissions.
KEY(order_id, product_id, download_id) used for organizing downloads on the My Account page
woocommerce_order_items - Order line items are stored in a table to make them easily queryable for reports
woocommerce_order_itemmeta - Order line item meta is stored in a table for storing extra data.
woocommerce_tax_rates - Tax Rates are stored inside 2 tables making tax queries simple and efficient.
woocommerce_tax_rate_locations - Each rate can be applied to more than one postcode/city hence the second table.