One thing that is noticeable is the yearly effect with October having the most searches - probably coinciding with some type of application deadlines.
Another interesting piece is to look at searches by different country - I think it's pretty interesting to see how low the US interest is for the GRE but it's the highest for the LSAT. Pakistan also shows up high for the MCAT which I found pretty interesting. Nepal seems to be high on some of them so it makes me wonder if anything is going on with that.
If Google maintains this database for a long enough time period it may be possible to see long term trends in the data - maybe the US had a much higher interest in the GRE decades ago.
Does anyone know if these other countries have test that have similar names? That would skew the results.