By default opera opens new tabs empty. Can I configure it so that upon opening a new tab the homepage is automatically loaded?
First, set your Home page, which can be done via:
Tools > Preferences > General
Or Ctrl + F12 and then to the General tab.
Now, call home with the home shortcut Alt + Home.
This will fire up a new tab set to your home page and skip showing the Speed Dial/blank tab.
Kadłubowski & Rads: Yes, you can tell Opera to open a new tab with your home page instead of the speeddial. Short summary; You can modify the keyboard shortcut and mouse gesture to do exactly what you want.