Many people sit at a long dinner table at a formal event.
A group of people are throwing food at a dinner table.
People cannot be sitting and throwing at  the same time. An event and dinner are two different things.
exists e1 s1 s2 x1 x2 x3 x4.(at(e1,x4) & n_event(x4) & a_formal(s2) & Theme(s2,x4) & at(e1,x2) & n_table(x2) & of(x2,x3) & n_dinner(x3) & a_long(s1) & Theme(s1,x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1) & n_quantity(x1))
exists e1 x1 x2 x3 x4 x5.(at(e1,x4) & n_table(x4) & of(x4,x5) & n_dinner(x5) & Theme(e1,x3) & Actor(e1,x1) & v_throw(e1) & n_food(x3) & of(x1,x2) & n_people(x2) & n_group(x1))