Is 'artisks' a word? (I met this word in 'The Invisible Man')
You may differ, finally, but my take on that use of 'artisks' by that character in that work is that it's a malapropism springing from 'artists' via the lips of the sage Mrs. Hall. If you read on, I expect you'll find that the artists do indeed come to the inn in the summer, and that Mrs. Hall has a vaguely disapproving yet tolerant attitude toward those same artists.
Of course, it could just be a typo in an ineptly proofed edition.