Most probably too large for your computer:
A = rand(12,3,5)
A =
A(:,:,1) =
0.3275 0.4565 0.9054
0.7983 0.5975 0.2010
0.2198 0.2999 0.8786
0.9899 0.9124 0.3179
0.9665 0.3451 0.1311
0.2861 0.9911 0.9365
0.9874 0.9247 0.4403
0.8435 0.8488 0.3430
0.0910 0.2928 0.0985
0.0995 0.6732 0.3981
0.2617 0.1184 0.3649
0.8339 0.7366 0.2909
A(:,:,2) =
0.0398 0.1426 0.6770
0.9303 0.4939 0.5339
0.0665 0.4595 0.4976
0.0761 0.6740 0.3230
0.3805 0.4837 0.0900
0.8389 0.8596 0.8293
0.9910 0.0807 0.7654
0.4896 0.4105 0.4247
0.6137 0.7339 0.8006
0.4384 0.6656 0.1509
0.2105 0.3942 0.8460
0.5686 0.6290 0.2638
A(:,:,3) =
0.0842 0.9096 0.2395
0.3705 0.6611 0.8899
0.7653 0.4083 0.4778
0.9416 0.9301 0.0006
0.8523 0.7219 0.8770
0.5199 0.7490 0.7645
0.8845 0.4652 0.6654
0.4324 0.0940 0.9906
0.0468 0.1547 0.0576
0.6182 0.9954 0.8048
0.1842 0.8711 0.4498
0.8104 0.3860 0.5313
A(:,:,4) =
0.4143 0.7380 0.2589
0.4286 0.1949 0.4761
0.2196 0.3809 0.5016
0.3815 0.2741 0.9400
0.2250 0.9047 0.9829
0.9862 0.1425 0.0772
0.5833 0.3206 0.3210
0.0632 0.4139 0.7289
0.5868 0.7736 0.5324
0.3161 0.4334 0.0550
0.7031 0.6694 0.0109
0.5341 0.4399 0.1195
A(:,:,5) =
0.5985 0.4265 0.0811
0.1229 0.3392 0.7524
0.2603 0.7418 0.4899
0.1817 0.9131 0.3994
0.2359 0.3633 0.3610
0.1934 0.6980 0.0690
0.7655 0.2662 0.3542
0.4334 0.5158 0.1679
0.9395 0.6295 0.1512
0.7503 0.1131 0.1357
0.9663 0.4720 0.1601
0.6951 0.1670 0.1415
A = num2cell(A)
A = 12×3×5 cell array
A(:,:,1) =
{[0.3275]} {[0.4565]} {[0.9054]}
{[0.7983]} {[0.5975]} {[0.2010]}
{[0.2198]} {[0.2999]} {[0.8786]}
{[0.9899]} {[0.9124]} {[0.3179]}
{[0.9665]} {[0.3451]} {[0.1311]}
{[0.2861]} {[0.9911]} {[0.9365]}
{[0.9874]} {[0.9247]} {[0.4403]}
{[0.8435]} {[0.8488]} {[0.3430]}
{[0.0910]} {[0.2928]} {[0.0985]}
{[0.0995]} {[0.6732]} {[0.3981]}
{[0.2617]} {[0.1184]} {[0.3649]}
{[0.8339]} {[0.7366]} {[0.2909]}
A(:,:,2) =
{[0.0398]} {[0.1426]} {[0.6770]}
{[0.9303]} {[0.4939]} {[0.5339]}
{[0.0665]} {[0.4595]} {[0.4976]}
{[0.0761]} {[0.6740]} {[0.3230]}
{[0.3805]} {[0.4837]} {[0.0900]}
{[0.8389]} {[0.8596]} {[0.8293]}
{[0.9910]} {[0.0807]} {[0.7654]}
{[0.4896]} {[0.4105]} {[0.4247]}
{[0.6137]} {[0.7339]} {[0.8006]}
{[0.4384]} {[0.6656]} {[0.1509]}
{[0.2105]} {[0.3942]} {[0.8460]}
{[0.5686]} {[0.6290]} {[0.2638]}
A(:,:,3) =
{[0.0842]} {[0.9096]} {[ 0.2395]}
{[0.3705]} {[0.6611]} {[ 0.8899]}
{[0.7653]} {[0.4083]} {[ 0.4778]}
{[0.9416]} {[0.9301]} {[6.3608e-04]}
{[0.8523]} {[0.7219]} {[ 0.8770]}
{[0.5199]} {[0.7490]} {[ 0.7645]}
{[0.8845]} {[0.4652]} {[ 0.6654]}
{[0.4324]} {[0.0940]} {[ 0.9906]}
{[0.0468]} {[0.1547]} {[ 0.0576]}
{[0.6182]} {[0.9954]} {[ 0.8048]}
{[0.1842]} {[0.8711]} {[ 0.4498]}
{[0.8104]} {[0.3860]} {[ 0.5313]}
A(:,:,4) =
{[0.4143]} {[0.7380]} {[0.2589]}
{[0.4286]} {[0.1949]} {[0.4761]}
{[0.2196]} {[0.3809]} {[0.5016]}
{[0.3815]} {[0.2741]} {[0.9400]}
{[0.2250]} {[0.9047]} {[0.9829]}
{[0.9862]} {[0.1425]} {[0.0772]}
{[0.5833]} {[0.3206]} {[0.3210]}
{[0.0632]} {[0.4139]} {[0.7289]}
{[0.5868]} {[0.7736]} {[0.5324]}
{[0.3161]} {[0.4334]} {[0.0550]}
{[0.7031]} {[0.6694]} {[0.0109]}
{[0.5341]} {[0.4399]} {[0.1195]}
A(:,:,5) =
{[0.5985]} {[0.4265]} {[0.0811]}
{[0.1229]} {[0.3392]} {[0.7524]}
{[0.2603]} {[0.7418]} {[0.4899]}
{[0.1817]} {[0.9131]} {[0.3994]}
{[0.2359]} {[0.3633]} {[0.3610]}
{[0.1934]} {[0.6980]} {[0.0690]}
{[0.7655]} {[0.2662]} {[0.3542]}
{[0.4334]} {[0.5158]} {[0.1679]}
{[0.9395]} {[0.6295]} {[0.1512]}
{[0.7503]} {[0.1131]} {[0.1357]}
{[0.9663]} {[0.4720]} {[0.1601]}
{[0.6951]} {[0.1670]} {[0.1415]}