how to send variable from Dialog class to main window class?

Hi all,
I have one main window class and another Dialog class....
I'm calling Dialog from Main window by creating pointer as shown below....

Dialog *d= new Dialog(this);
d->show();

and performing all the operation in Dialog(which actually creates a creates and updates a table widget and then displays in the Dialog)
But i want to Display that table widget inside the Main window...
Please give me some hint how can i do that?

My try:
after updating table i'm emitting a signal and that signal is used in Main window to display the table, but displaying table program crashes......