Basic "warmup" exercises at the start of every class. Everyone does them (or should be doing them). Some of the more obvious exercises like the wrist exercises are precursors to actual techniques themselves, e.g. ikkyo wrist pin, nikkyo, sankyo (2 versions), yonkyo and gokyo. Others like hip rotations, are preludes to koshi-nage techniques. And others like fune-kogi undo (boat rowing) are "ki" building exerises, focusing on joint alignments and moving from "center".

What other exercises do you do and what do they mean for/to you?

Or are they simply "warmup exercises", in preparation for actual training?

We do a whole set of techniques called aiki taiso. They are basically Aikdio movements that are broken down and help acheive muscle memory. Some of them include Ikkyo undo, Fune kogi undo, sayu undo, etc. I believe they were developed by Koichi Tohei.

Yes, but what else do these exercises imply other than "building muscle memory"?

As an example, funi-kogi undo is more than just "boat rowing", and I would suggest more than just "building 'muscle' memory". In fact I would go so far as to say, fune-kogi undo (or even sayu undo) has nothing to do with building 'muscle' memory but is intended to teach something else which is fundamental in what makes "aikido" aikido.

If you catch my drift...

umm no I odn't quite catch you.. but a lot of the taiso techniques are used when you actually do a technique. Such as the fune kogi undo. We use this during a technique called kata otoshi. Where you are behind the attacker and place both your hands on his shoulder as your hips go back your hands follow and it throws him down. Just like fune kogi the hands/arms follow the hips.