diff --git a/banking_breakdown/ui.py b/banking_breakdown/ui.py
index e046d11..9d680a7 100644
--- a/banking_breakdown/ui.py
+++ b/banking_breakdown/ui.py
@@ -283,7 +283,14 @@ class MainWindow(QMainWindow):
             self._list_widget.takeItem(self._list_widget.row(selected_item))
 
     def _assign_category(self, category: str):
-        print(category)
+        indexes = self._table_view.selectionModel().selectedRows()
+
+        row_indices = [self._table_view.model().mapToSource(index).row()
+                       for index in indexes]
+
+        df = self.get_statement_data()
+        df.loc[row_indices, 'category'] = category
+        self.set_statement_data(df)
 
     def _handle_apply_click(self):
         category = self._list_widget.selectedItems()[0].text()