What are the main causes that led to the rise of the novel in the 18th century?
As your question (and your additional comments) imply, the novel as a genre literally blossomed in England in the first half of the 18thC. Although the novel form had its beginnings in Spain and France in the late 17thC. (for example, Don Quixote and Gil Blas), it became the most popular form of literature in England by the mid-18thC. Several factors--some of which you outline above--came together in the early 18thC. to encourage writers to focus on novel writing and to create a demand for it with the reading public.
Much of what I am going to say I take from an important book on the novel--Ian Watt's The Rise of the Novel (1957)--which attempts to analyze the various social and economic causes of the novel's popularity in the context of novels by Richardson, Defoe, and Fielding.
Watts argues persuasively that, on a cultural level at the beginning of the 18thC., the literate public was becoming intensely interested in realism, generally defined as the desire to understand how real people make their way in the world as they experience the best and worst of what life offers. In other words, the reading public wanted to see their lives reflected in a literary form, and the form that concerned itself with everyday life was novel. Novelists like Defoe and Richardson, relatively early in the century, were writing about the struggles of middle-class people and using experiences that were clearly recognizable to the reading public.
A second, but equally important, element in the rise of the novel was economic. As industrialization increased, a middle class developed rapidly in England. With the increasing middle class came more education and leisure time, both ingredients in the popularity of the novel as more people had time to read and more money to buy books. The publishing industry grew exponentially in the first half of the 18thC. as the expanding literate class demanded more material, and the material that appealed most to this class was the novel.
Although the rise of the novel is more complex than I've outlined here, the combination of a desire for the realistic depiction of life and the rise of the middle class are two of the most important components of the novel's popularity in the 18thC.
there are some points in my mind but i can explain it.1)spread of education and publication.2)Rise of democratic class.3)The rise of middle class.4)attraction for Female readers.5)individualism.6)New prose style.6)declined of drama.7)Public demand.
please elaborate these points in to understand the question.but in more simple words.