So, it's rather badly damaged, but for 50p I felt it was worth it to log the registration numbers.

The dish has two registrations internally 81160 for 15th September 1887 and 94543 for 25th February 1888, but no trademark.
There are a few examples of 81160 in the Glass Gallery, which correspond with the pattern around the edge of the dish, and the example in Jenny Thompsons book.
However, 94543 has no examples in the Glass Gallery and no description in JTs book. So, I'm thinking it's possibly the pattern used on the base

particularly as Greener produced other items with multiple numbers for different patterns.
I can try and get better photos later on when I can get to my table.
edited to say, measures 17.5cm x 13cm x 5cm
Lindsey