Generally, the author is referring to Ulysses" want to travel to places that no one has traveled to before. As he travels to the new unseen world, the margin of which he has not seen fades. In other words, as he travels the world there will be less for him travel. He just wants to start an exploration that will make him a great explorer and the person that has seen everything. .
The meaning explained above specifically applies to the poem because Ulysses wants to travel to a new unexplored land before he dies. The author says "how dull it is to pause, to make an end, to rust unfurnished, not to shine in use." This means that he that he wants to travel and never stop or he will have an incredible need to continue on his journey. He must complete his journey or he will feel like his purpose was not served.
These lines specifically apply to things that I want to do before I die. There are places that I want to go, things that I wish to see, and people that I want to meet. There are many things that I will do before I die and my margin will never fade away because I will always find something new that I wish to do. I will do what has not been done, I will see what has not been seen, and I will meet with people that I thought I would never meet. .