Rummikub - Maximum number of tiles in hand
No, there is no maximum. I'll link the rules, but there's nothing to quote, as there is no limit.
Tiles in hand count against you, so there is some risk involved in this strategy.

The first player who manages to play all their tiles wins. The other players add up the numbers on the tiles remaining in their racks, counting jokers as 30. They each score minus the total of their remaining tiles, and the winner scores plus the total of all the losers' tiles.