A = [1 2 3 4; 5 6 7 8] % Create a 2-D array with the vectors in it.
A = cat(2, [1 2 3 4], [5 6 7 8]); % Create a 2-D array with the vectors in it.
For more on cell arrays, like in Jesus's answer, see The FAQ. One advantage of cell arrays is that each cell can contain anything : matrices of all the same or all different sizes, string, tables, even other cell arrays. Any MATLAB variable can be put into the cell and each cell can be totally different.
Another variable that can contain matrices is a table, though I think each column in a table must contain the same size array.