Tales. Tales can be long or short, but when we talk about long stories, 'tales' can also be used. For instance, 'fairy tales' can be quite long when they are fully developed, with complex plots and multiple characters.
Tale. For example, 'He told a long tale about his adventures.'
Another option is 'protracted story'. It implies that the story goes on for a considerable time. You might also hear 'drawn-out account' used in a similar way.
Epic. An epic is often a long and continuous narrative, usually dealing with heroic deeds and events of great significance.
One could say 'epic novel' as another term for a long fictional book.
Tale. A tale is a kind of long - detailed story. It usually has some kind of plot or sequence of events. For instance, fairy tales are often long - detailed stories that are passed down through generations. They can be very elaborate and full of details.
Memoirs. Memoirs are written accounts of one's own life experiences, which is very similar to life stories. They often focus on specific periods or aspects of a person's life and are a great alternative term.