Below you can see the front-view size comparison of the Olympus TG-3 and Olympus E-M5 II. The Olympus TG-3 is clearly the smaller of the two cameras. Its body is 12mm narrower, 19 mm shorter and 14 mm thinner than the Olympus E-M5 II.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.