Marking all the volumes in your personal library with an Ex libris ownership stamp - from the library of [add your name] - is now a thing of the past. But when books represented a far more costly investment as a part of household income, this was a way of ensuring that if you lent a treasured volume to a friend you would be more likely to get it back. It also asserts that you have a collection, not just a few titles.
Today only some institutions feel the need to brand their goods with a mark of ownership but we can still enjoy the decorative artwork used to individualise personal property. If you could afford to print your Ex libris, they would have your name on as three of these do; or you could buy a blank set and add your name by hand in the space available. These examples from 1890-1910 include a depiction of a book though often the illustration was unrelated to reading and could be simply a landscape or a decorative plant.