I understand the OP's approach, but I am not sure I understand VonNemo's remarks. The truth table for must indeed have the following form:
(Though I prefer the following order of the first two columns going down: F F, F T, T F, T T. If T is replaced by 1 and F by 0, we get 00, 01, 10, 11, which in binary notation means 0, 1, 2, 3. Following this systems helps prevent missing or repeated rows.)
p q | p \/ (not q)
T T | ?
F T | ?
T F | ?
F F | ?
However, the OP's truth values in the last column are incorrect. For example, when p = T and q = T, is T because disjunction is true if at least one of the arguments (in this case, p) is true.