Possible Clues:

• Bookish hostess
• Chat show hostess's work gets a cheer
• Celebrity with a book club
• Big name in talk
• TV host with her "OWN" network
• Billionaire with a book club
• Sofia's portrayer in 'The Color Purple'
• Hit TV show that ended in 2011
• She signed off with the words 'until we meet again'
• Sethe portrayer in "Beloved"