Pushing a book across a table, applying the same amount of force all the way through

Say I push a book along a table (applying continuous force until I reach the edge of the table). I apply as much force needed for the book to travel in constant velocity. Since the book is traveling in constant velocity across the table, Newton's first law would have it that the net force applied horizontally would be zero, meaning that the force of my push on the book is counter-acted by friction. However, if the net force is zero, how is the book able to move at all?