Question: How do I plot a more than 1000 piece of data as a line plot?

I more than 20000 data points on a an excel file and i want to plot one column against the other. So I imported 10 data points from each column seperately and tried ploting it as a normal plot but it would not work. I kept on getting error messages like 

plot([CosAa,CosBb]);

Error, (in plot) incorrect first argument [Array(1..10, 1..1, {(1, 1) = 0.83333e-2,
 (2, 1) = 0.166666e-1, (3, 1) = 0.249999e-1, (4, 1) = 0.333332e-1,
 (5, 1) = 0.416665e-1, (6, 1) = 0.49999800000000004e-1, (7, 1) = 0.58333100000000006e-1,
 (8, 1) = 0.666664e-1, (9, 1) = 0.749997e-1, (10, 1) = 0.83333e-1}), Array(1..10, 1..1
, {(1, 1) = .232849, (2, 1) = .231323, (3, 1) = .234375, (4, 1) = .238953,
 (5, 1) = .245056, (6, 1) = .245361, (7, 1) = .24231, (8, 1) = .237732,
 (9, 1) = .232239, (10, 1) = .231323})]

CosAa and CosBb are the imported data.

How ever it would work if i plotted it as a ScatterPlot. below is the data points I was trying to plot?

How can i plot this as a line plot?