There's a share batch code with letters and numbers in brackets at the end of the project name on your indexing page when you have the batch open. Will you copy and paste it here so we can see your batch. We really can't answer the question without seeing which project it is, the project instructions and the document itself.
US, Massachusetts—Boston Tax Records, 1822–1918 [Part Q][M3PY-FGG]
Yes, you can assume the surname for the people in the groupings per the project instruction: