Is there a consensus on if blocking king and pawns together so opponent cannot move in Tablut (Hnefatafl) is stalemate, or a win?
This set of rules for Saami Tablut (&quot;Historical Hnefatafl&quot;) includes an explicit handling of that case:

7b. If the attackers surround the king and ALL remaining defenders, then they
win, as they have prevented the king from escaping.

And it's even broader in this set of rules, which captures the king if he cannot move (even if the king's side has other pawns that can move):


The king himself is captured if he is surrounded with enemy pieces or restricted
squares in all four cardinal points, so that he
cannot move in any direction.


(emphasis added)
The case is also present in the rulesets for other variants presented on this page.
In this summary of the history of the game, under the section of &quot;correcting the errors&quot; of Murray's mis-translation of the rules, they say that Helfrid included this additional rule (that agrees with your link to the PDF by Zorya):

If a defending piece is beside the king and the king is trapped, the companion is taken rather than the king.