Hey,
1st option:
KeyPressFcn callback, see UITable callbacks. Create a CellSelectedFcn callback first that saves selected cell in a property so you can access it from anywhere. Then with KeyPressFcn detect if button 'insert' is pressed, if yes, insert a row into the Data property of uitable.
If you want only to add the row only at the end of the table, then KeyPressFcn will be sufficient,
2nd option:
I have made a demo app for this purpose here. If you add the vector with any values to the component, it will expand
app.UITable.Data(end+1) = zeros(1, width(app.UITable.Data));
