There are several options besides the title of your PDF that you can set when creating your PDF's.
1. You can set the layout (landscape or portrait) for your PDF map.
2. Create a PDF map with a map only, no legend. This means the map image will be bigger because it uses the space where the legend would of been.
3. Create a PDF map with a map on one page and the legend on a separate piece. This also results in a bigger map since the legend is on another page.