I recently bought a copy of, "The Grand Inquisitor" and, after a few days, I noticed that the title of the book on front cover was written partially in cyrillic. Does the cyrillic on the front mean anything or is it just for aesthetic purposes?
It means nothing. It just reads "The Grand Inquisitor" in English with a few Cyrillic letters thrown in to replace English letters that they look vaguely similar to. This is an example of Faux Cyrillic.
For what it's worth, these are the letters used:
д - used for the "a" in "grand", actually represents /d/
и - used for the "n" in "grand", actually represents /i/
б - used for the "d" in "grand", actually represents /b/
ф - used for the "q" in "inquisitor", actually represents /f/