when I look inside UITableView class scope by using "Jump to Definition"
As a general rule, learning a language by reading the source of its standard library is a bad idea.
For various reasons, system libraries in most languages often contain unusual constructs that should never appear in "normal" code.
Swift is not the worst in this respect, but I would still advise using "Jump to definition" etc. only for navigating within your own code.
Topic:
UI Frameworks
SubTopic:
UIKit
Tags: