这么些 is a colloquial fixed phrase combining 这么 ('such/so') with the indefinite quantifier 些 ('some'). It means 'so many/so much' and is used before a noun, often with a tone of surprise, complaint, or emphasis — similar to 这么多 but more conversational. You typically hear it in spoken Chinese, not formal writing. The phrase carries a subtle emotional weight: the speaker is remarking that the quantity is unexpectedly large.