We had something similar, just without the hallway wall, see picture
However, the kitchen width was only about 220 cm... You now have a proud 120 cm more available, and I didn't exactly find my kitchen very small – two people could cook comfortably, with 340 it should be even better :)
Personally, I think 340 cm is too little for watching TV. So: just try it out at home.
Otherwise, you now have enough suggestions to experiment with.
Tip: Possibly move the side window and/or only have a 1-meter-wide middle wall as a TV mount.
I still favor option 1! :)
Oh, and we didn’t have a round table, but a 220 cm long and 110 cm wide dining table, so extra long :)