Can I assign the same keyword to more than one page?
No, you should not assign the same keyword to more than one page.
If you optimize your pages for similar terms, your rankings might suffer from keyword cannibalization: you’ll be ‘devouring’ your own chances to rank in Google!
If you cannibalize your own keywords, you’re competing with yourself for ranking in Google. Let’s say you have two posts on the exact same topic. In that case, Google can't discern which content should rank highest for a certain query.
As a result, they’ll all probably both rank lower.