This is the 7791st most frequent Polish word.
masę
"Masę" means "a lot" or "mass" in English, depending on context.
Here, 'masę' is used to describe a large quantity of items metaphorically.
Mam masę książek do przeczytania.
I have loads of books to read.
In this case, 'masę' conveys an overwhelming or considerable amount intuitively.
Zasypała go masę problemów.
She overwhelmed him with a lot of problems.
'Masę' functions here to generalize a significant amount of solvable issues.