A 3D matrix is created, and data stored, simply by calling out a third dimension:
A = randi(100, 5, 4, 10); % Creates random integer matrix of size 5x4x10
This format works for pretty much any multidimesional matrix generation command (zeros, ones, rand), and assigning specific values just means calling out a third dimensional index value.
A(1,1,1) = 100; % Set first value to 100
A(:,1,1) = 100; % Set first column, first sheet to 100
I'm not sure how this applies to your data though, because all of the variables you've specified seem to just be row matricies, at first glance. Do you have a piece of information you want to assign to every index in a 3D matrix that isn't shown here?