Minimization of DFA, Table Filling Method or Myhill-Nerode Theorem

I want to know, what if the DFA is merged states. So if my DFA starts with q0 and then have (q0,q1) state it goes to with an ‘a’ for example. How do I do the table filling method.

I tried to rename the merged state, for example turning (q0,q1) to q4 for example. But then the issue is when I try to do the table filling. With the input in the Automaton, I get only one state, sometimes the final state. So do I mark it.

For example, I renamed (q0,q1) to q4. Now in the table, if I want to find out the marking for q0 and q4. With an ‘a’ I get q4,q4 for both of the state and with ‘b’ I get nothing from q0 and q2(final state) from q4. I know since q4,q4 does not exist I do not mark. But I only get one state, which happens to be the final state. Do I mark q0,q4 part of the table or do I leave that blank aswell