Essentially, the problem that I am experiencing is that the legend overlaps the gnuplot graph that I am trying to plot as illustrated in the following diagram.
You can control location of the key by providing a set of coordinates:
set key at 25., 5000.
These values correspond to the data coordinate system. Alternatively, you can specify graph coordinates:
set key at graph 0.1, 0.9
(close to top-left position).