You definitely don't want to call plot repeatedly inside your loop.
Here is a suggested approach where I created the plot outside the loop and then just update the data for each of the lines in the plot during the loop. Note that running this in Answers won't show the animation. It will just show the final result.
This definitely runs faster than your current code (I tried it on my desktop Matlab).
Adapt as needed.
t = (0:1e-3:6*pi).';
data = [t sin(t) cos(t) 2*sin(t) -2*cos(t)]; % example data (18850 rows of data)
figure
% initially, just plot the first two points to initialize the plot
h = plot(data(1:2,1), data(1:2,2), data(1:2,1), data(1:2,3), data(1:2,1), data(1:2,4), data(1:2,1), data(1:2,5));
grid on
xlim([0 max(t)]) % manually set the x and y limits so Matlab won't automatically adjust while looping
ylim([1.5*min(min(data(:,2:5))) 1.5*max(max(data(:,2:5)))])
for i = 3:numel(t)
for iLine = 1:numel(h)
h(iLine).XData = [h(iLine).XData data(i,1)]; % add points one-by-one to the existing lines
h(iLine).YData = [h(iLine).YData data(i,iLine+1)];
end
drawnow limitrate
end
