I approach a table, ask if they are ready to order or if they need more time. One, or sometimes all of the people at the table say. "We're ready to order."
Okay, ten seconds, okay, twenty seconds, "Okay, well let me give you all a little more time to make your decisions."
"No, we're ready now."
Okay, ten seconds, okay, twenty seconds, okay, now I'm starting to stare off into space or looking around at my other tables who might be waiting for me to get them something while you're monopolizing my time while you read the menu.
If you aren't ready, say you aren't ready. I will come back. Not only is it completely uncomfortable for me to stand over you at your table in silence, but it is also rude to all the other guests in the restaurant who are also paying for my time and attention.