'Tasks' markers are a good way to annotate source files with to-do's or bug entries. The Tasks view lists them and I can use them as shortcuts to the source ...
You can remove by exploring below path in your eclipse. Window -> Preferences -> Java -> Code Style -> Code Templates. In the code tree you have the templates.
Just including the text TODO in a single-line comment will add that comment's text to the Tasks view, enabling you to keep track of tasks in one location.