-Why the observable matter in the universe is packed togrther in galexies and is not evenly distrubted throughout space..........

It may be because of the supermassive black hole present at the center of galaxies, which have tremendous gravity thereby giving the galaxy a packed shape.

HAVE A LOOK AT THIS WIKIPEDIA LINK:

http://en.wikipedia.org/wiki/Supermassive_black_hole

Mysterical dark matter is present at the edges of the galaxies which maintain the matter in a definite region of space and this matter don't have the properties of the usual matter. DArk matter and dark energy and two opposite forces in this universe responsible for its present state. About 30% dark matter is present in this universe and 69% dark energy.The dark energy bind matter wheareas dark energy expands every thing .you can also refer to big rip theory,youwill definitly get the solution.