@JVC
We can reduce the polycount without changing too much the details. You can clearly see in my test, it's hard to spot the different before checking the mesh, it reduce 4 poly per book, considering there is roughly ~100 books that means a reduction by 400 polygons which is a lot.
Also you have to take into account the race is going fast, usually that's the kind of details people will never see, because they are going way too fast. Don't forget you can also add normal map to fake some rough surface without actually adding polygons.
@ArDanWol
It's a very nice desk with a lot of very cute details. However there is some improvement that can be done:
1) You don't have to do the books because we will use a model from the bookshelf.
2) Can you join objects by real life objects. I just joined the table to show you how it can be done. That's easier to edit them
3) Can you use a bit more of the same "mesh" for instance, in the picture A you could use the same 3D mesh and do an extrusion instead of adding a new plane. There is no concrete rule when it should be used and when it's better to extrude, Usually if for instance the table is a bit bigger than the wall I won't use the extrusion (to save polygons) otherwise I would try to make them connected.
4) You can also remove faces that are invisible to the player, like this quad inside the wall of the table/desk
5) The small details are nice, however, the pencil is a bit overkill, the books are also too high poly but has I said we will use the model from the bookshelf. The petrol lamp is nice, ideally the glass should be transparent so we can see the flame inside (and yes it's possible to do it).
I would recommend to clean the geometry and then to show me the result. Once the geometry is clean and okay then we can start the texturing.
I hope my feedback wasn't too harsh

. If you have a question just ask me.
Sam