I have twice started this reply ... and in the light of Veronica's rapid comments, have now twice revised my reply

- and I apologise in advance that this reply is rather long and has little to do with glass. I think Anne is going to throw this into the cafe. I'm not going to amend a third time.......sorry jp. but thanks for the enebriated response.

Veronica - wow, thanks for both the culinary and history lessons. Thought the history of the liqueur type drinks very interesting - maybe C19 Regency sipping of drinks was an improvement on Hogarth's 'Gin Lane and Beer Street depravity.
As to the history of the Greek Key Motif/Design - it seems that it was a common ornamental pattern from the second half of the C18 (Georgian) onwards, both in architecture and jewellery (at least for the U.K.), petering out in the late C19 - so guess it may not have arisen solely from the Grand Tours - which were mostly to Italy, I believe.
It appears that I may have always been wrong, but in the sense that the 'key' motif' is normally understood to represent the outline, quite literally, of a key - then my piece fails in this respect. However, I hear what you say, and have looked at your link, and the outlines of the various parts that make up repeating patterns. I would think that you are right in what you say, and that the idea of a 'key motif' should not be seen as needing to actually look like a key in outline.
When you say that my pattern looks Edwardian (you may well be correct) - I have seen many examples of the traditional (key shape) key motif pattern, but don't recall having seen this precise pattern.
You refer to 'Edwardian Sharaton' - and by this I take it that you are referring to what is a sub-division of the Georgian revival i.e. copying the Adam style which originates in the late C18. This was a revival 'style' popular from about 1875 through to something like the end of the Edwardian period (1910).
Is historic design your 'thing' - rather than glass?
Anne - although I remain unsure of the use of these bowls, but whatever the purpose, then yes, I agree that my example may well be for a similar use, as it looks very much like yours. What were they for, desert of some kind?? Unless I have missed it somewhere, you don't give the size of your underplates.
Don't think I will collect any more of this design - one is enough.