If you’ve used firefox, you know you can change the preference to allow you to open links what would normally open in a new window to instead open in a new tab.
However there doesn’t seem to be a similar setting for safari.

You can always hold down the command key while clicking on the links, but here’s a tip to set Safari to always a open them in a new tab.

First, be sure that Safari is not running, then open Terminal and enter the following command

defaults write com.apple.Safari TargetedClicksCreateTabs -bool true

That’s it, when you launch Safari, all links that would normally open in a new window will now be opened in a new tab instead.

To remove the change you just made, enter the following command in Terminal

defaults delete com.apple.Safari TargetedClicksCreateTabs