Mac Pro :: Slow Beach Ball - Take Ten Second For Dictionary To Come Up After Clicking On Look Up Dictionary

I still get beach balls when doing the basic of things. For example, it sometimes takes 10 seconds for the dictionary to come up after right clicking a word and selecting "look up dictionary". Then again, sometimes it is instant. Similar things happen when looking at a document that is a .pdf, for example, and I want to save as a jpeg. Whether I go to "save as" or through the "print" and then selecting "save as a pdf", it can beach ball for 8-10 seconds.

I thought it may have been a ram problem and from another thread I discovered the "activity monitor" and have that running constantly in the dock showing me "System Memory" and for the stuff I'm doing, it hardly ever gets close to half the pie chart.