Most of the culture ships are named after punchlines to jokes about war, violence, and excessive use of force.
Part of the joke is that the culture partly abhors the use of violence but yet at the same time finds itself constantly engaged in acts of violence to protect itself and in the aid of those it feels morally required to aid.
Many of the warships have anti-war views, but believe in the necessity of some violence to achieve a greater good. Thus the culture feels the need to let off angst about war in different ways and the names of the ships is one of those ways.
"Of Course I Still Love You" for example, is a joke about how those who attack others are sometimes in abusive relationships, making excuses for their behavior. In this way the ship is joking about how the harm it inflicts on others is ultimately for the greater good of everyone, though it appears abusive. Also this is something a parent might say after disciplining a child, much in the same way the culture's superior fire-power can discipline their misguided enemies.
"Just Read The Instructions" is a little more difficult. I assume this is referring to the complexity of military hardware and spaceships and how they are often put into the hands of those who don't understand what they're using. If someone has a different take that's more obvious, I'll edit this later.
Part of the reason that someone might name ships after culture ships, is the Culture is a utopia similar to Star Trek's Federation. In some ways representing a possible pinnacle of mankind. Also Iain Banks passed away rather abruptly from Cancer, so many of his fans have been contemplating his passing recently and thus looking for ways to do tribute to his rather strong body of literary work.
Many of the ships are only named in passing, or are on the sidelines of a conflict, so many ships are not always important characters in a story. Both ships are from Player of Games and are friends with one of the drone main characters. I can't recall offhand if they had any significant interactions and I can't seem to find any detail about it online.
From Consider Phlebas
By their names you could know them, Horza though as he showered. The Culture's General Contact Units, which until now had borne the brunt of the first four years of the war in space, had always chosen jokey, facetious names. Even the new warships they were starting to produce, as their factory craft completed gearing up their war production, favored either jocular, somber or downright unpleasant names, as though the Culture could not take entirely seriously the vast conflict in which it had embroiled itself.