In the scene pictured above from “I Love Lucy” episode Lucy Meets Charles Boyer we see Ethel speaking to Lucy on the set of Ricardo’s hotel room in Paris. In the background we can see the owl bookends we looked at  before in the Ricardo’s living room, later they moved to a shelf in  Ethel’s living room when she got Lucy’s old furniture, and now the are in the Paris hotel set. The book title appears to be “An Introduction to French” and a possible candidate for this book is:

• An Introduction To French by Robert F. Roeming (Amazon Link), Charles Edmund Young, published by D. C. Heath and Company, Boston, 1951
• Seen also listed on Abe Books