This possibility exists for almost any book that has come to us from the time before mass printing. In the days when manuscripts were hand copied, there was a lot of room for error, although there were various safeguards that classical Islamic scholars used to try to reduce the possibility of intentional or unintentional error.
Regarding Kitab Sulaym, it is possible that some of it is correctly ascribed to the transmitter who called himself Sulaym ibn Qays and some comes from other people. (This is also true for any other work.) However, in any case, the content of Kitab Sulaym seems to be mostly traceable to an early era of Islam so it most likely reflects what was going on in that time regardless of exactly where every bit came from.
However, proving tampering also requires some proof or at least proof of motivation, and I don't think we have any evidence to suggest that specifically Aban ibn Abi Ayyash tampered with it. If there are interpolations, they probably came in later copies.
The only real exception to this rule is the Qur'an, because it was transmitted and memorized by so many people, that it would have been very hard to add things to it without causing mass objections.