How to take an average of 7 rows of all the column and save into the following row and next 7 until the data finisih?

Then you would take the mean of each column of that matrix. The result would be 1 x n x m, and we will have averaged the 7 elements in each column together that you wanted averaged. Now we can take average of each row and that would create the desired result that you want

Here's an example:

M = [1:2401];
M = reshape(M, 49, 49); % Dummy matrix of 49 x 49 dimensions
% Now we reshape the matrix into 7 x 7 x 49, and use the squeeze function
% to get back a 7 x 49 matrix, which contains average of 7 consecutive
% numbers in a column
B = squeeze(mean(reshape(M,[7,7,49]),1)) 
B = 7×49
           4          53         102         151         200         249         298         347         396         445         494         543         592         641         690         739         788         837         886         935         984        1033        1082        1131        1180        1229        1278        1327        1376        1425
          11          60         109         158         207         256         305         354         403         452         501         550         599         648         697         746         795         844         893         942         991        1040        1089        1138        1187        1236        1285        1334        1383        1432
          18          67         116         165         214         263         312         361         410         459         508         557         606         655         704         753         802         851         900         949         998        1047        1096        1145        1194        1243        1292        1341        1390        1439
          25          74         123         172         221         270         319         368         417         466         515         564         613         662         711         760         809         858         907         956        1005        1054        1103        1152        1201        1250        1299        1348        1397        1446
          32          81         130         179         228         277         326         375         424         473         522         571         620         669         718         767         816         865         914         963        1012        1061        1110        1159        1208        1257        1306        1355        1404        1453
          39          88         137         186         235         284         333         382         431         480         529         578         627         676         725         774         823         872         921         970        1019        1068        1117        1166        1215        1264        1313        1362        1411        1460
          46          95         144         193         242         291         340         389         438         487         536         585         634         683         732         781         830         879         928         977        1026        1075        1124        1173        1222        1271        1320        1369        1418        1467
% Now we take average of each row
C = mean(B')
C = 1×7
        1180        1187        1194        1201        1208        1215        1222

I've haven't used data from your excel sheet but if you are able to read the data from your excel sheet and make a matrix like the one used above, then this should work.

Refer to these documentation links to learn more about the functions used here: squeeze, reshape, mean

Hope this helps!