If you have an existing UITABLE called "T1", representing some data and want to display the computed output in a separate UITABLE called "T2", with only one column named as "Output",that can be done using the code below:
f = figure('Position', [100 100 752 250]);
a = [10 20 30 40 50 60 70 80 90 100];
T1 = uitable('Parent', f, 'Position', [25 50 700 75], 'Data', a);
T2 = uitable('Parent', f, 'Position', [100 180 78 40], 'Data', sum(a));
T2.RowName = ;
If, for example you want to display the sum of all values of a column in the current UITABLE, you can do this by adding a row at the end of the current UITABLE.
More information on this can be found in the MATLAB Answers Thread below:
For your second question, it is possible to use a "CreateFcn" callback which is invoked when MATLAB creates an object. You can use the callback to load the required variables when the GUI window appears.
More information on callbacks can be found in the documentation link below:
Hope this helps.