The term tear page, at least in the advertising world, refers to a reproduction of a page from a phone book. The origins of the word come from the days when the pages were actually torn from phone books in order to use them as references.
Tear pages are most often photocopies, but as more companies make their books available via the internet, it is increasingly common to see them in printed from a pdf format. Tear pages are usually black and white, but sometimes, usually only at client request, they are printed in color.
Tear pages are primarily used by ad firms who specialize in directory advertising and are used mostly in the research part of ad development. Tear pages can give a good sense of how competitive a market is in particular region and gives the company and it's clients a good idea of how big an ad the client should obtain in the book and how it should be placed..