1) REMOVING THE SEDER PLATE FROM THE TABLE
OPINIONS: The Gemara relates that the custom was to remove the table from before the one who was leading the Seder (like the opinion of Rav Huna). The RASHBAM explains that in the time of the Gemara they used to eat at small, individual tables. However, today, when everyone eats together at one large table, it suffices to move the Seder plate to the other end of the table. What is the common practice?
(a) The SHULCHAN ARUCH (OC 473:4) rules like the Gemara's conclusion according to the Rashbam, that the Seder plate should be moved across the table before one recites "Mah Nishtanah" so that the children will be aroused to ask questions.
(b) However, the MAGEN AVRAHAM (OC 473:25) writes that even this is no longer necessary. The reason the Seder plate is removed is to arouse the children's curiosity when they see that the Seder plate is removed before the meal. This goal will not be achieved today, because the contents of the Seder plate are merely symbolic and are not eaten. The removal of a plate that contains food that will not be eaten during the meal will not arouse the curiosity of the children.
Even though the ELIYAH RABAH points out that some of the things on the Seder plate are eaten, such as the Matzos, nevertheless many of the Poskim make no mention of the custom to move the Seder plate because of the Magen Avraham's argument.
The CHAFETZ CHAIM (in SHA'AR HA'TZIYUN 473:78) writes that the VILNA GA'ON and PRI MEGADIM did not rule like the Magen Avraham (and therefore the Chafetz Chaim does not mention the opinion of the Magen Avraham in the Mishnah Berurah). Nevertheless, the grandson of the Chafetz Chaim, Rav Hillel Zaks, affirmed that the Chafetz Chaim himself did not move away the Seder plate. This is the practice in many households today.
(c) The practice of the Yemenite Jewish community is to cover the entire table and everything on it with a tablecloth, a practice which is certain to arouse the curiosity of the children.