Good afternoon Lynne,
Welcome to the Apple Support Communities!
I understand you would like to listen to audiobooks on your Apple Watch Series 3. Currently, this feature is planned for the watchOS 5 update:
Apple Newsroom Press Release - June 4, 2018
watchOS 5 adds powerful activity and communications features to Apple Watch
A new feature for developers allows music, audiobooks and meditation sessions from apps such as Pandora, Audible and 10% Happier to be synced to Apple Watch for playback offline without the user’s iPhone nearby.
Pricing and Availability
watchOS 5 will be available this fall as a free update for Apple Watch Series 1 and later and requires iPhone 5s or later on iOS 12. watchOS 5 will not be available on the original Apple Watch. Features are subject to change. Some features may not be available in all regions.
Like you, I'm looking forward to the watchOS 5 update!
Enjoy your day!