Towards the second evening she reached the irregular chalk table-land or plateau, bosomed with semi-globular tumuli. (42.11)
So the landscape here is covered in rounded hills, or "tumuli," that Hardy compares to "bosoms"? Yes, this is weird. Yes, this needs a closer look. What do breasts generally signify? They usually symbolize fertility, life, and sustenance. So the land here seems to be nurturing and fertile, but it's really "chalk[y]" and, as Marian calls it, "starve-acre."