Individual butter pats are shallow for ease in getting a bit of butter on the knife, can't recall ever seeing them with any sort of grate, a drainer just wouldn't be necessary. Can remember Mom using nut dishes in the '60s, they stayed on the table until the end, and twenty-odd years ago, as a free-lance bartender, after prepping my bar would usually help the caterer or club staff set up, there were often nuts placed on the table prior to seating, either in individual dishes/cups at each setting or in larger bowls or compotes, they also remained on the tables throughout.
This excerpt is from a 1916 cooking magazine, showing butter pats and nut dishes, noting their being in place before dinner was announced:
~Cheryl