Here's a link to an article by Graham Hodges about miniature Georgian silver sugar tongs (of course your tongs are not Georgian but I guess the same reasons could apply in this case too):http://www.ascasonline.org/ARTICOLONOVEM176.html
"1. They were made for toy sets of silver-ware;
2. They were made as samples for travelling salesmen to display the maker's arts;
3. They were made by apprentices and made smaller to use less silver;
4. They were made for people to take on picnics, as part of a "travelling" set of silver-ware;
5. A patron had specifically tasked the maker with a commission for a smaller pair of tongs."