Interestingly they actually have a function room that transforms into a Skittle alley when not in use. If you plan to eat here please ensure you check ahead of your visit it is open and serving food.
Opening hours vary year on year and can be seasonal. Be aware that on UK bank holidays and school holidays standard opening hours may differ also. To avoid disappointment, It's always worth calling ahead (+44 (0) 1451 850358) if you plan to visit to ensure they are open. You can also check their website for opening hours: https://www.donnington-brewery.com/the_farmers_arms_guiting_power.htm