Can you please tell me what is the meaning of the ending of The History of the Siege of Lisbon by José Saramago?

As there are two key components to José Saramago’s novel, there are also two endings. One part of the story is that of the proofreader-turned-writer Raimundo Silva. The other part is The History of the Siege of Lisbon, an actual phase of Portuguese history that Silva finds himself rewriting. Saramago concludes the re-written history first. As the Christians take over Lisbon, their victory is clinched when the inhabitants in the last fortress surrender. However, one soldier takes it upon himself to carry out a final act. Inside the great mosque, the muezzin, who calls Muslims to prayer, calls out to Allah. This particularly zealous Christian soldier races up the minaret’s stairs,

-and with one blow from his sword beheaded the old man, in whose blind eyes a light flickered at the moment of death.

In the next paragraph, the very last one in the book, comes the end of Silva’s story. Exhausted at having completed his history, he crawls into bed beside Maria Sara. In answer to her questions, he tells her that it is finished and ends with the muezzin’s death. She wants to know about two key characters. He says that Mougeime and Oorouana will leave for Galicia rather than stay in Lisbon. As they drift off to sleep, Silva admits that staying would be more logical. The idea of departure can be seen as representing Silva’s decision, helped by Maria Sara’s prompting, to embark on the creative life rather than stay within the confines of his proofreader job.
https://books.google.com/books?id=K3yTai3swv8C&source=gbs_navlinks_s

This fascinating book, published in 1989, explores the duality of a proofreader, Raimundo Silva, charged with correcting a book on history, but whose inner conflict leads him to question his role in writing what future generations will believe.
Written by Portuguese author José Saramago, this novel makes grammar, spelling and punctuation into a thriller. How does word choice change meaning? How are we impacted by the way moments are captured, and described?
The novel is built in two arcs, one historical, and one in the present. And that's not the only challenge Saramago sets up: He only uses commas and periods, no other punctuation. Critics have complained that this might give the work a meandering quality. For example: (p63):
… a traditional Portuguese meal of fried fish and rice with tomato sauce and salad, and with any luck, the tender leaves of a lettuce heart, where, something not many people know, nestles the incomparable freshness of the morning, the dew and mist, which are one and the same, but warrant repetition for the simple pleasure of writing both words and savouring the sound.
New York Times critic Edmund White writes, "He jokingly refers to his own long-windedness -- which differs from real pomposity in that it is never dull or humorless." But the style and structure of the novel underscore the content and form: In this ending, a courtship between two proofreaders, the author is playing with time.