This site is insane.
If you mow everything, and leave every tile unimproved (so ignoring the camp and pasture already pictured) you've got
14 commerce (city + 13 river tiles)
13 hammers (city + 4 hills + 4 pants)
and a food left over.
Better still: look carefully at the shape of the river. Two of the tiles are corners, and two are hills, but all of the other nine tiles can be watermilled.
Max commerce is easy - 19 cottages, and the extra food means one less health you need to dig up. You might screw around with mines and so forth along the way.
GPP Farm is still easy - Farm everything that's flat except the bananas (including the cow). Hills get mines.
Max production is a bit more fun. Mine all the hills, pasture the cows, temporarily camp the ivory, and watermill the rest (yes, even the bananas, which should probably get a planation first until the city is up to size). At size 14, you are pulling in 19 more hammers, 4 more commerce... with 9 more hammers to come with Replaceable Parts (losing the ivory camps), and another 4 with Railroads. Oh, and a surplus food.
That leaves 4 grassland plains tiles unworked, in addition to the rice (which can't be watermilled because it is on a river bend). Working a rice farm gives three surplus food, so including the surplus from above you can work four workshops for another +4 hammers (with eight more to come with guilds and chemistry).
So lets see, by era...
Ancient: well, you can mine one hill, and build 4 camps. It looks like there might be one or two tiles along the river you can farm to work the jungles. So you only get to work 3 or four production tiles... call it three. 9P/6C @ 5 pop. Rah
Classical: hooray for Ironworking. Three more mines, the cows, and the rice can be dug out and improved. You can also free up more food by clearing the jungle from the camps and bananas. There's enough food at that point to run all four mines, and the four workshops (temporarily located on the river for the commerce). 23P/13C @ pop 11, with an additional 1P/1C per pop available up to pop 15.
Medieval: Machinery comes in, so three workshops move, replaced by 5 watermills - but the camps are still better than the watermills, so those stay. Guilds, so workshop production goes up. 32P/17C @ pop 15, +2P/1C @ 16, +2P available for each pop up to 19.
Renaissance: Replaceable parts comes in, so the camps give way to the more productive watermills. Chemistry adds another boost to the workshops. 41P/13C @ pop 15, +3P/1C @ 16, +3P for each up to 19.
Industrial: Railroads, so +4 from the mines. Biology comes in, so that one farm we've got gives an extra food; as We are emphasizing hammers, that means a watermill gets ripped up for a workshop. Electricity comes in, so the 8 remaining watermills kick in another 16C. 58P/30C @ 19.
Or step into the magical world of State Property - I'm not going there, it makes my head hurt.