The * represents the fact that there is a slight pause there between section. The rest of the notes are close together because they are in quick succession. Watch To make it easier for it to be played , the bottom e- and B-string have to be picked with your middle finger, and for the G-string use your index finger. This is because, as you can see in the tab, you often alternate between picking the B- and G-string. When you have to pick the e-string just use your middle finger, then for the ne (azchords.com)