According to Rav Shlomo Zalman Auerbach, z"l, as cited by the Kof-K, tables do not require tevila. However, he is cited in the same Kof-K article as having seemingly allowed omitting tevila of refrigerator shelves only because they are part of the appliance:
Refrigerator Shelves- If the food is not placed on these shelves directly there is no requirement for tevilah. Be’er Moshe 4:99, Tevilas Keilim 11:10, Minchas Shlomo 2:66:8, Shalmei Moed page 555. Some say it is always exempt because it is butel to the refrigerator (Shalmei Moed ibid).
What reasoning is employed by Rav Shlomo Zalman, z"l, to rule leniently with regard to tables (that apparently isn't usable by shelves)?