Dyanamic Table row height incremented by some pixels

In our project we have a dynamic table in which user can add rows to table by clicking 'AddRow' button.

My problem is that when a row added to the table, the row height of all the existing rows are incremented by some pixels. Same way if user continue adding 10rows, then the table row heights are incremented to a large extent.

My addRow() method is as below-

public void addRow(int noOfRow) {
    	int maxSize = tableLength+noOfRow;
    	for (int i = tableLength; i <= maxSize; i++) {
            Select dataType = new Select();
            dataType.addItem("Name");
            dataType.addItem("Email");
            dataType.setSizeFull();
            dataType.setImmediate(true);
            dataType.setData(i);
            dataType.setCaption("DataType");
            dataType.addListener(this);

            Select format = new Select();
            format.setData(i);
            format.setCaption("Format");
            format.setImmediate(true);
            format.setSizeFull();
            format.setEnabled(false);
            format.addListener(this);

            Label example = new Label("NA");
            example.setSizeFull();

            TextField field = new TextField("");
            
            HorizontalLayout addBar = new HorizontalLayout();
            addBar.setSizeFull();
            addBar.addComponent(new Label("NA"));
            
            listing.addItem(new Object[] {i, field, dataType, format, example, addBar}, i);
            tableLength = i;
    	}
    	log.debug("DataGenApplication - addRow() end");
}

Thanks in advance.

Original Table and After adding 10 rows, table looks like below -