I have some basic data 250 rows deeps and 16 columns wide. Every two sets of columns is a set of X and Y coordinates, respectively.

I was going to plot it. So I created a XY scatter and started to add one set at a time. The first set (columns A + B) was fine. However, as I continue to add the data I get awful lag. By the fourth set of columns, every click results in 10s of lag after selecting the columns. By the eighth set of columns the computer is basically locked up.

This isn't a cheap computer, something is going on in Excel and I don't know what. Any ideas?