It has been awhile since I played Saleron's Gambit so unfortunately I do not remember what I did with the chests & tiles at the time. However, I just looked at that area in the toolset and it seems there are no scripts attached to the large chest, and no scripts in the module at all that reference either the tag or resref of the tile items, so as best I can determine it seems there is not in fact anything to do with them. The only relevant script does nothing but give players a little XP for unlocking the chests with the Tiles.
IIRC, Carlotta's Compound was sort of a Thieves' Guild, so it may be the chests are just there to provide a little local color. We are perhaps to assume they were there to test out the lock-picking skills of thieves seeking to join, and they incidentally give PCs a chance to show off any lock-picking skills they might have. Alternatively perhaps they were meant to be part of some small quest or puzzle that due to time limitations or oversight or some such issue on the author's part was never completely implemented.