is relative. Boats like the Mainship need larger tabs because the operate at lower speeds. I have 42" x 12" and with 200HP I can get on plane, but without the tabs that's a maybe. Also other benefits as mentioned, the high profile might make a MS heel with wind on the beam, or being able to put one side down a little to knock down spray.
Don’t Worry About Which Trim Tab is Moving
Bennett Trim Tabs operate the reverse of what you might think. The port trim tab lowers the starboard bow. Conversely, the starboard trim tab lowers the port bow. The control is wired so that all you have to do is press the control in the direction you want the bow to move. The proper use of Bennett Trim Tabs becomes second nature after a short time.
Probably more than you might ever want to know about trim tabs:
How Do Bennett Trim Tabs Work? - Bennett Marine