What would be considered the major events in Treasure Island?

This is a great book, which means that there are a lot of twists and turns in the novel. Let me give you two examples to show you what a major event would be. 

First, Jim Hawkins and his mother find a treasure map in their inn. This discovery starts the novel. Without it there would be no mystery, no adventure, and no antagonists or protagonists. Immediately after this, Livesey and Squire Trelawney charter a ship to get the famous treasure of pirate Flint. 

Second, another significant event is when Long John Silver is able to find a way onto the Hispaniola. Later on he is found to be a duplicitous person. He poses as a chef but he is actually a pirate who is also looking for the treasure. In the end, he becomes the main adversary and gains the respect of the reader. Finally, he leaves with a portion of the treasure.