Their diagrams are pretty close to what you should do. Here are two ideas- the green squares are small 'poofs', squishy ottoman/chair/stools or little upholstered squares- they can get tucked under a table or something when not in use. I think that I like the second layout better.

This is really very very helpful. Thanks for your advice meanwhile i have tried to design some layout can you please look at it as well and advice me what can be done to utilize the space under the stairs. I don;t mind if we remove the dining table.