Final answer:
Knowledge authors typically use a Rich Text Editor to format knowledge articles because it offers predefined formats, code snippets, and tools like find or replace in a user-friendly interface without requiring extensive coding knowledge.
Step-by-step explanation:
The editor commonly used by knowledge authors to apply predefined formats, code snippets, table of contents, and conduct find or replace text operations for a knowledge article is the Rich Text Editor (RTE). The RTE offers a user-friendly interface to format text, insert media, and use various built-in tools to enhance documentation without the need for direct HTML or Markdown coding. Editors like HTML or Plain Text require knowledge of coding, whereas Markdown is simpler than HTML but still code-based. The RTE simplifies the process with a toolbar and buttons for common functions.