Hi Jon,
Thanks for reaching out!
You would need to have 8 actual tickets be purchased in order for the stock to automatically decrease by 8. There is not an out of the box way to decrease the stock by a number greater than 1 for a single ticket purchase (such as if you created a “Table” ticket). However, you might take a look at some of the extensions from WooCommerce that allow you to bundle products, or possibly this one that lets you set minimum and maximum quantities for products. So for example, you could try using the Chained Products extension, which allows you to automatically add other products (such as tickets) to the cart for free when one product is purchased.
I’m sorry I don’t have a more straightforward solution for you here, but I hope this helps! Please let me know if you have any other questions.
Thanks,
Jennifer