This is a simple icon meant to represent an address book. It's a rectangle stood on end with rounded corners and the @ sign in the middle. The right hand side of the book is hatched with short lines to represent the rings that hold the pages inside the binder.
Related to Address Book Icon
Related icons are the icons with matching tags, as well as all messaging icons. All icons are in the same flat style. You can either download free PNG icons or buy SVG vectors