Numbers usually mean holes
The number tells you which hole to play. A tab that says 5 points to hole 5, but you still need a breath mark to know whether it is blow or draw.
Breath marks vary by tab system
Some tabs use plus for blow and minus for draw. Others write blow and draw directly. Direct words are easier for beginners and easier to scan on mobile.
5 blow = C55 draw = D56 blow = E56 draw = F5
Chromatic tabs need slide information
A chromatic harmonica has a button that raises the pitch. A complete tab should tell you whether the slide is out or in before you start the note.