Antique Pitcher and Tumblers on Tray, What is its use?

I acquired this at an estate sale. It was made by Roberts & Belk (silverplated I think because it has the Aladdin’s Lamp and prior to 1892 I think because the ampersand sign is rounded at top).

My question is what was its use? The four tumblers fit on the tray and the pitcher has no handle, but has a stem. Did it have a specific purpose?

Thanks.

Also, I heard that sometimes the Aladdin’s mark was on sterling too but I have not been able to confirm. Anyone know?

Thanks.
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