I couldn't actually determine the exact line of code causing the problem , but even if you set the table KeepTogether property to true, at least for me, it completely ignores it and keeps acting as if you hadn't, splitting tables across pages.
Instead, I had to tell the top row to "KeepWith" the next x rows in the table, and then it didn't split. (Actually
snow rider, I only tried it with x=1, as the tables only had 2 rows.)
I’ve noticed the same behavior — KeepTogether often seems unreliable in PDFsharp tables. Using KeepWith on the top row is a smart workaround, especially for small tables. It would be great if PDFsharp offered more consistent table pagination controls in the future!