Full frame at 3 meters, F9 and 50 mm gives you 2.15 meters of DOF. You can actually see this in your photo: from the cloth on front of the table to the wood pattern from the back-left side, everything is focused.
There can be two problems why your shot is blurry: 1) movement of camera / people, 2) the auto-focus in low light is not accurate and has focused way behind the people. There also appears way too much noise reduction, with some crappy algorithm, which has caused a significant loss of resolution.
By the way, at F4 you still get 87 centimeters of DOF, so you can get all the people in focus and get 2 stops more of shutter speed (80).