When it's capitalized:
* As part of a title: "The Table of Contents for this book is quite detailed."
* As a formal heading: "Table of Contents" (usually centered and in a larger font)
When it's not capitalized:
* As a general description: "The table of contents helps you find specific information in a document."
* In casual conversation: "I glanced at the table of contents to see what chapters were in the book."
Think of it like this:
* Formal vs. informal: If you're writing a formal paper or report, use the capitalized form. In casual writing or speaking, the lowercase form is fine.
Let me know if you have more questions about capitalization!