This is a famous poetry(in nice calligraphy writing) which was written by 杜甫 regarding his friend 李白 and other 7 famous poets who, in his opinion, were "8 Immortals Indulged in Wine" (Yeah it was a thing back then. If you can write beautiful poems while you are drunk, you must be a genius haha). The part on this cup is the part only about 李白.
Both of them are titans of 唐诗. Actually they are the best two in most people's opinion. And the best part about their friendship is that 杜甫 is such a Realism poet while 李白 is famous for his Romantic poetic style. Their style are totally opposite yet they cherish each others work and their friendship deeply.
I don't know how to translate it since it is hard to translate poems.
Here is the wikipedia page about this poem: 饮中八仙歌