One cell in each row of a QTableWidget contains a combobox
for (each row in table ... ) { QComboBox* combo = new QComboBox(); table->setCellWidget
I think you want to take a look at QSignalMapper. This sounds like a typical use case for that class i.e. you have a collection of objects where you hook up to the same signal on each but would like to know which object emitted the signal.