In Safari | Preferences... | General, we have the ability to "Open links from applications: in a new window | in a new tab in the current window". If I highlight text on a web-page in Safari and right-click, I get a popup that allows me to "Search in Google". When chosen, the present behavior is to load my google search in the same window. Please add a feature to load the google search in a new tab or new window (so that we can search on the present highlighted FOOTNOTE/MINOR/CURSORY search term of interest and not lose our place in our MAIN document by having to go back -- especially if the search leads to multiple link sidetracked browsing).
This would be more appropriate as a feature request for Safari. Tabs are an application-level concept and are not something that WebKit is aware of. You should file an enhancement request against Safari at <http://bugreport.apple.com/>