How to set "Go to address" to open the address in a new tab in safari
You can use added hot-keys to make a whole set of different actions happen when you click a link.
This is the way I have mine set in Safari Preferences…

This way, a simple click will open the link in the current page,
 Cmd ⌘ /click will open it in a new Tab but not activate it &amp;
 Cmd ⌘   Shift ⇧ /click will open it in a new Tab &amp; also bring it to the front.
Setting the first dropmenu to 'Always' will also set a new Tab to be opened if you select the URL in another application &amp; right-click select 'Open URL'