I had no problems reading it and plotting it with xlsread (although I cannot determine if the data are plotted correctly because I have no idea what the data represent). (I am using R2020a.)
Try this:
D = xlsread('Radar_frames_Mat.csv');
x = D(1,2:end);
y = D(2:end,1);
figure
mesh(x, y, D(2:end,2:end))
grid on
