Below you can see the front-view size comparison of the Fujifilm X-E3 and Fujifilm X-A5. The Fujifilm X-A5 is clearly the smaller of the two cameras. Its body is 4 mm narrower, 6 mm shorter and 3 mm thinner than the Fujifilm X-E3.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.