Choping, it seems, is a practice in Singapore when you reserve a table while you are getting your food at public eating areas. The problem (or is it one?) arises when there are more groups of patrons than available tables. Your little tissue marker stands on the table while other people wander around looking for a place to plant their little markers, so they may better eat their laksa.
It seems to me that choping is efficient. If you can reserve a table by choping, the inefficiency is that you show up to eat earlier, and grab a table earlier, than you would like to. But once you have a table you don’t have to hurry so much. If you can’t reserve the table by choping, the inefficiency is that you go to the food stalls without lines. (The very best food stalls can have lines of half an hour or more.) Without choping you are less willing to wait in those lines because the good tables are going away.
Choping increases the ease of getting the very best food of Singapore. And that food is very very good indeed.
Choping may not be efficient elsewhere.
Addendum: Al Roth comments.