Q. There are two tables in the room. I know that there were candles (and only candles) standing on one of them when Shabbos began, and the table became a bosis. However, the candles were taken away by an aino Yehudi and I don’t know which table they were on. Are both tables muktzah?

A. Placing muktza on top of an object before Shabbos turns the item underneath it muktza as well, since it becomes a Bosis (O.H. 310: 7, Mishna Berura – Introduction 308). However, that is only if the muktza was placed there with the express desire that it should lie on top of that object. For example, if one placed candles on top of a tray before Shabbos, with the intention that they remain there, the tray becomes a bosis (or base) to the candles and becomes muktza too. Poskim disagree whether it is necessary to have in mind that it should stay there until the end of Shabbos or just during “bein hashmoshos” or twilight (See O.H. 309: 4, and Mishna Berura 21).
Although the prohibition of muktza is assumed by most Poskim to be only rabbinical, in some instances we are stringent when in doubt, as we would be with a biblical prohibition. We do not necessarily follow the dictum of “Sofek derabanan lehakel”(when in doubt be lenient). Two reasons are quoted for this (Magid Mishne – Yom Tov 2: 7). We call it a “Dovor sheyesh lo mattirin,”or an item that will become permissible tomorrow, and one should rather wait and eat it when it is allowed. Also, our Sages saw fit to be stringent on muktza, since it is easy to transgress. Shemiras Shabbos K. (20: n. 7) quoting Horav Sh. Z. Auerbach zt”l, explains further that there is a difference on doubtful muktza that is consumed, in which case you should be stringent since the principle of “yesh lo matirin” applies, and when the issue is only moving it, then you can be lenient.
Horav Shlomo Miller’s Shlit”a opinion is that if the Gentile worker was instructed before Shabbos to remove the candlestick on Shabbos or it is known that this is going to happen, following the opinions quoted above, the tables would not become bosis and could be moved.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a