Try mock roman shades - immovable but lined, heavy fabric will soak up some sound. You can also upholster the chair seats or add cushions to them and put a rug under the table (4' wider and longer) if you don't already have one. For dinner parties use a table cloth with a pad underneath it to absorb the clink of crystal and silver and put a muffler on table noise.

I would suggest roman shades too, definitely lined. You can open them completely for the view, but close them when and if you want, for privacy and energy savings. I have a sunroom full of windows and a double skylight. I have sheers during the year and in the late fall I add curtains (I made valances that cover the rods when empty) The fabric ideas by decoenthusiate will help.
I found these great roman shades when reading another post...
http://www.hunterdouglas.com/php/asset.php?id=9163&width=962&height=528