All of these tests are indicators of liver function, and they are only mildly elevated. Many things can cause elevated liver enzymes, including medications and alcohol, which are the most common culprits. Infections can also cause it, including Hepatitis, CMV and EBV (the viruses that causes mono and mono-like illness), and many others. If you have any risk factors for hepatitis (IV drug use, multiple sexual partners, blood transfusion, etc), then it is probably worthwhile to be checked for hepatitis. Otherwise, have your doctor take a look at your medications to see if any of them could be causing it, but since they are only mildly elevated, you probably won't even need to stop the meds...the levels will just need to be followed to make sure they aren't getting worse. There are many many other things that can elevate liver function tests, but they are less common.
GGT is specific to alcohol intake as the liver metabolizes alcohol. If you drink...even occasional binge drinking, then try to stop. You other liver enzymes are just slighlty over normal. Some medications and diseases (hepatitis) can alter liver function. Tylenol and cholesterol lowering drugs are some common causes of decreased liver function. The good news is that the liver is the only regenerable organ in the body and if we treat it well, it can bounce back. Well wishes to you!