It means: I am not good at lying. However, I do not dislike (the concept of) lying (in itself) all that much. More colloquially: I am not good at lying, but I am not really against the concept of lying. Now, word for word: 僕は (I + topic particle) 嘘をつく (lie + object particle + to tell) のは (nominalization of the verbal phrase "to tell a lie" + topic particle) 得意 (good at) ではない (not) .でも (however) 嘘をつく (lie + object particle + to tell) こと (nominalization of "to tell a lie") 自体は (itself + topic particle) それほど (that much, or, "to that degree") 嫌い (dislike) ではない (not).