The 3rd bar on the top has a run. They're written as 8th notes, but that doesn't make any sense to me. Why are they written as 8th notes? Or does it actually rhythmically make sense?
The values don't really matter. It's in 3/4, so all that's left is nothing!. However, the whole piece has come to a stop - there are pause marks all over the previous notes in that bar. So it's more of an anacrucis to start the next part off again. Notice all those noteheads are smaller than usual, so it gives the performer carte blanche as to how quickly he plays them, and the tempo will recommence on the first notes of bar 4.
Notes written in a tiny font like this are grace notes, and it's understood that
- they don't count against the beats in the bar they're in
- you're supposed to play them with free rhythm, almost certainly not all the same length.
(Grace note passages are usually just one or two notes, but Romantic composers, especially Chopin, went way overboard with them.)