May one serve ice cubes in a serving bowl on Shabbos?
It is forbidden to actively melt ice on Shabbos through crushing it and the like. It is disputed whether it is permitted to inactively cause ice to melt, such as through placing it near a heat source, such as the sun. Practically, the custom is to be stringent, unless it is a time of need. A further dispute is added when one is simply removing the ice from its cold environment, such as the freezer and is simply placing it in room temperature. Nonetheless, in a case that one has no intended use of the resultant water that will melt as a result, and one plans to simply throw it out, then it is permitted to inactively cause the ice to melt through placing it in room temperature. Accordingly, there is no prohibition involved in preparing a serving bowl of ice to serve at one’s meal so long as one does not plan to make use of the resultant water that melted from the ice. There is no need to first add water to the ice tray, although doing so certainly adds to the allowance. If, however, one does plan to use the melted water such as to drink and the like, then whether it is permitted to serve the ice in a serving bowl is subject to the above mentioned dispute regarding removing ice from its cold environment. In any event, even in such a case, it is permitted to do so if one first places some water in the bowl and then places the ice cubes in to it.
It is permitted to have a serving bowl of ice cubes at one’s meal so long as one does not plan to make use of the resultant water that will melt from the ice. If one does plan to use the melted water such as to drink and the like, then one is to first place some water in the bowl and then places the ice cubes in it.
 Admur 320/16; Michaber 320/9; Shabbos 51b
 See both opinions in Admur 320/16; brought also in 318/25-27 regarding melting fat; See Michaber [lenient] and Rama [stringent] 318/16; 320/9
 Admur 318/27; 320/16; Rama 318/16
 The following Poskim are lenient: Sheivet Halevy 7/40; Az Nidbaru 6/3 and 34; 10/10; Tzitz Eliezer 6/34-30; Divrei Yatziv 159; Shabbos Kehalacha 3 17/3 and 27. The following Poskim are stringent: SSH”K 10/3; 1/74, as is the simple Halacha ruled by Admur that one may not cause frozen water to melt. [320/16] Rav SZ”A as brought in Mioreiy Hashabbos.
 SSH”K 10/1; Piskeiy Teshuvos 320 footnote 22 [old] 320/13-14 [new]
The reason: As the melting prohibition does not apply in a case that the melted item will be going to waste and one does not have intent to melt it. [See Admur 320/17; Taz 320/7; M”B 320/32; Meor Hashabbos 3/13-98; Shabbos Kehalacha vol. 3 17 footnote 84 and Tosefes Biur p. 157]
 As one has no intent to drink the melted water but rather only to use the ice and it is thus similar to throwing ice in ones sink which is allowed due to that the liquid will be going to waste
 See Admur 320/16; Michaber 320/9; Shabbos 51b
 See Admur 320/16; Michaber 320/9; Shabbos 51b; Piskeiy Teshuvos 320 footnote 152