Fixed table and saved to database

db.json

@@ -0,0 +1 @@
+{"_default": {"1": {"-Serial Number-": "1234", "Brand": "dell", "Grade": "7", "Name": "jb"}}}

main.py

@@ -55,8 +55,9 @@ def main():
         if event == 'Add Computer':
             new_computer = add_computer()
             existing_table = window["table"].get()
-            existing_table+= list(new_computer.values())
+            existing_table.append( list(new_computer.values()))
             window["table"].update(existing_table)
+            db.insert(new_computer)
 
     # Finish up by removing from the screen
     window.close()