What is the function of 的多 in 中国人爱喝茶的多?
中国人 is the topic of the sentence, which explains its position at the beginning. So, "As for Chinese people, ...".

爱喝茶的 is a nominalisation of 爱喝茶 "love to drink tea": hence "people who love to drink tea".

Finally, 多 is just the stative verb "many".

So, "Among Chinese people there are many who love to drink tea."