Only when you are eating.
For as long as your host has a napkin on her lap.
Just for the main course.
For the entire meal.
Next to the soup spoon.
To the left of the butter knife.
To the right of the butter knife.
Besides the plate when the course is served.
Go to the kitchen and replace it yourself.
Ask the waiter to replace it.
Apologize to everyone at the table and ask if someone has an extra.
Pick it up discreetly and use it again.
There is no set rule.
The host does not begin serving the meal.
The base of the bowl.
Whatever is comfortable for you.
None of the above.
Whatever way is comfortable to you.
A knife and fork.
All of the above.
Here's an interesting quiz for you.