I am going to assume that your "data" is a long character vector with no delimiters.
v = char(randi([48 57],1,64)) % example vector
% to get a reshaped character array
vreshaped = reshape(v,8,[]).'
% to get as a numeric array instead
vnum = str2num(vreshaped)
% or
vnum = str2double(num2cell(vreshaped,2))
% or
vnum = str2double(mat2cell(v,1,ones(1,numel(v)/8)*8)).'