Try to import on line at a time in a for loop. Then within that loop convert the line into an array. You would then save that array to an index of a cell array. then at the end you can either keep the cell array, or you can find the longest row and pre-allocate a matrix of that size, then copy the data in the cell array over to the matrix, leaving the rest of the indexes as empty strings. The for loop would look like this:
cell_array = {};
for i = 1:numlinesinfile
current_line = import current line in file
cell_array{i} = current_line
end
