Each row is a state and each column is the symbol that was just read off the tape. So the first row & first column mean "I have just read symbol 0 and am currently in state A".
The cell in the table describes which actions to perform. The first row & first column has "1RB" which means: "replace the symbol on the tape with '1', shift 1 symbol to the right on the tape and switch to state 'B'".
The cell in the table describes which actions to perform. The first row & first column has "1RB" which means: "replace the symbol on the tape with '1', shift 1 symbol to the right on the tape and switch to state 'B'".
The state 'Z' corresponds to the halting state.