actually i cant move the dining table close to the kitchen as tahst the main entrance to our house.if i put dining table in that area,the entry would look congested.the rooms adjoining it are gallery which leads to mastre bedroom and another bedroom.

You've to consider some points before designing you celebration hall. 1) It should have proper sound proofing if there is too much of noise. 2) There should be more of decorative lights to give proper effect. 3)In this hall, there should be corner sitting or grid sitting, the center space or the pathway should be defined for the movement. 4) The cooling system whether its air cooling or air conditioning, it Should be effective, so must consult a professional for that. For any other help, you're most welcome

It 'might' look a bit odd. Why not have a curtain and slide it when you need day light. It will be better if you post the pics of the room.

Just because you want to use the space below the stairs, do not just add drawers or shelfs unless you reaalllyyy need it. I would suggest go for adding something green to your house. Its healthy by adding air purifying plants. These plants are nowadays available in most of the nurseries and moreover Green patch in the house gives a beautiful look to the house and is also good for eyes ( the green color). Below are few picture to motivate you for Green patch or Indoor garden.