Here’s a little etiquette about napkins and folding napkins.
When you are a guest at a friends house or at a restaurant this is what you do with a cloth napkin when you leave the table.
1) If you are leaving for good, you leave the napkin on the table. Placing the napkin on the table means you are not coming back. This means you are done, finished.
2) If you are coming back to the table, like to go to the bathroom, you leave the napkin on the chair, bunched up. This tells your waiter you are coming back, you are not finished.
So now you know and you can be real cool and act like a civilized animal.