Many problems that arise in making egg salad, chopped liver, tuna fish, etc. (Besides the issue of LOSH).
Setting a Mouse Trap on Shabbos;
Is One Allowed to Carry (With an Eruv) a Sweater to Shul for After Shabbos? Taking the Key When You Could Hide It;
(Squeezing materials.) using a "MOP"on Shabbos;