Who is Kundera or the character "I" from The Book of Laughter and Forgetting and what is their importance?

Throughout the novel, Kundera or the character "I" appears to give presumably factual accounts and historical events that happen as a backdrop to the vignettes. By juxtaposing the historical accounts with those of the fictional characters, the re-tellings give more color and personality to the characters by making the reader feel as though the character "I" exists in the same space as these characters.