I would use the following syntax:
You haven't shared your station names, so this approach uses the values in the table (loaded as strings).
fileNm = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1099640/HMCSV.csv';
opts = detectImportOptions(fileNm);
opts = setvartype(opts,'Station','string');
data = readtable(fileNm,opts)
data =
Station Lithium Chromium Manganese Iron Copper Zinc Arsenic Lead
_______ _______ ________ _________ _______ ______ ______ _______ ______
"37" 8.6933 17.043 31.42 0.43167 7.2967 23.88 0.90333 6.8783
"36" 7.285 14.395 39.4 0.57 7.115 22.765 0.75333 7.32
"35" 7.7 13.127 28.95 0.57667 7.4383 24.7 0.85833 7.8133
"34" 7.93 12.038 33.483 0.39333 6.3717 18.45 0.86333 7.185
"33" 8.725 12.698 42.533 0.32167 5.7483 15.4 1.07 7.2917
"32" 7.37 19.663 27.817 0.30667 4.0317 19.683 1.0167 6.165
"31" 8.0333 17.587 30.7 0.4 4.61 23.25 0.81667 7.415
"30" 8.51 16.963 36.992 0.41333 3.5433 20.87 0.86667 7.295
"29" 8.1567 17.867 33.767 0.46833 4.9833 19.033 0.86333 7.5883
"28" 9.15 19.218 33.967 0.56667 4.405 23.333 1.4167 8.0367
"27" 8.3633 13.497 28.717 0.47833 4.69 26.282 0.96 7.46
"26" 9.56 11.593 36.863 0.52333 4.98 21.958 1.2767 8.7983
"25" 11.983 9.605 49.7 0.55 8.5117 15.57 0.92333 8.2083
"24" 10.657 11.422 43.1 0.40167 5.805 20.7 1.285 8.31
"23" 10.002 12.2 38.367 0.51 4.65 18.417 0.99167 7.4617
"22" 9.6783 13.623 32.333 0.435 6.0417 16.697 1.0067 9.3067
heatmap(data.Properties.VariableNames(2:end),data.Station,data{:,2:end})
The values will appear if you make the figure bigger (maximize it on your computer).