Something has come up — perhaps it is time for a scheduled program or there are items that are really more important to take care of at a particular meeting. The motion that was being discussed needs to stand aside, so to speak. This is the time to make a motion to lay on the table. A caution: this motion can't be used to get rid of a motion or postpone it. Also, there is no such motion as “table a motion.” Lay on the table may be what people mean when they use this term.

Lay on the table needs a second, is not amendable, and is not debatable.