Follow the demo; see inline comments for details.
% Create 3 timetables of different heights
dt = datetime(2000,1,1,0,0,0) + minutes(0:30:5000)';
TT1 = timetable(dt(1:100),rand(100,1));
TT2 = timetable(dt(1:85),rand(85,1));
TT3 = timetable(dt, rand(size(dt)));
% List all timetables in a cell array named "allTT"
allTT = {TT1, TT2, TT3};
% Get heights of all timetables
heights = cellfun(@height, allTT);
% Loop through each timetable and move the last column into
% the table T; use NaNs as fillers.
T = array2table(nan(max(heights), numel(allTT))); % You may want to name your variables here.
for i = 1:numel(allTT)
T{1:heights(i),i} = allTT{i}{:,end};
end
