small engineering components with simple model and one 2d view are often less than 200kb
medium size files like the floor plan of a 3 bedroom house, a model with windows roof, a concept drawing maybe 1 or 2 mb
A large file would be above 5mb, not easy to email unless one has a gmail account or similar.
A huge file would be more than 10mb, gmail accounts handle up to 25mb.
I have a few huge files, they are around 25mb, when TC19 ver 43.2 loads them they take 2 mins to load and total system memory left out of 24GB is about 8Gb, when running small files total system memory used is only about 4.5GB.
These are only my known rule of thumb, other users may have different views, hope it help Alvin,