Open a new terminal tab from the current terminal using command
Solution 1:
You have to do this through AppleScript, but it can be executed from the command line via osascript
osascript -e 'tell application "Terminal" to activate' -e 'tell application "System Events" to tell process "Terminal" to keystroke "t" using command down'
Credit: StackOverflow - Open new Terminal Tab from command line (Mac OS X)