Quite a few of those are medical jargon that I wouldn't expect anyone to know unless they were a doctor (or perhaps had experienced the particular ailment/procedure themselves). Several of them refer to biology or zoology jargon I wouldn't expect most people to know unless working in those fields. Others draw upon loan words from Yiddish - again, a relatively limited pool of people using them regularly.
It seems like it's deliberately arduous under the guise of "anyone at a level 8-8.5 IELTS score (the advertised goal of the site) would know these". Ergo, if you don't (and most won't) then you need to enroll in their course. "OH NOES, MY ENGLISH MUST BE TERRIBLE"
Note that most of the answer options are deliberately chosen to either rhyme and/or alliterate to additionally confuse the reader. You need to be incredibly well read and/or dabble in dozens of different fields of interest to know all these words.
It looks like more of an advertising hook to me than actual helpful free study material! Honestly, I find it kind of irritating that they're trying to manipulate people this way so transparently.
Yes, English does have a massive vocabulary but I'd counsel you to take this test with a grain of salt. It's not a realistic goal for a language learner. It's not a realistic goal for most native speakers! You're probably not as overwhelmingly under-prepared as this "test" is trying to make you feel.
The reason you couldn't get access to any more materials is that they want you to join and pay for them! They want to you to panic and join their classes or subscribe to their curriculum.