About 3 times a month I will get a call, usually by someone who is quite upset, asking if I would be able to come over and touch up damage on the top of a formal dining room table. When I ask what has happened they explain that the chandelier or a part of the chandelier has fallen on their table. What most commonly has happened is that someone decided to clean the chandelier and discovered they can spin it on it base. This allowed them to stand at the side of the table and simply spin the chandelier to clean it, one arm at a time. After a few cleanings, they manage to spin it enough times to unscrew the base from the ceiling and it drops. Generally, if it is heavy enough to pull the wires apart and drop to the table, the damage will be extensive enough to require a complete refinishing. This is a costly and depressing mistake, especially when the table is brand new. (This actually happened to me, twice. I happened to notice the gap between the base and the ceiling when I glanced up one morning; it about half a spin from falling. When I asked the housekeeper about it she admitted she had been spinning it. When she retired I forgot to mention it to the new housekeeper and was again lucky enough to look up and see the gap.)
If you want to clean or dust your chandelier, move the table out of the way. Covering your table is not a guarantee that you will be safe. We have refinished several tables that were covered with thick packing blankets and still experienced significant damage. Chandeliers are heavy, have sharp edges and crystals, light bulbs that shatter, etc. Moving the table and then working from a small ladder is the best plan.
Another common mistake is made when removing the table leaves. When one person tries to remove a leaf without a helper, he or she will generally grab it on each side and lift it straight up towards the ceiling, where it comes in direct contact with the chandelier. Bang! Damage! It is best to use two people, lift it parallel with the table top, and then walk it down to one end of the table before tipping it up.
So, beware the simple chandelier! And while you are thinking about it, go check for a gap, just in case someone has been spinning your chandelier.