1. "Like to the lark at break of day arising
From sullen earth sings hims sweet song to heaven."
This a metaphor comparing Viola and her song to a lark ascending at the break of day, singing melodious songs to the sky.
2. "So much our grace offending."
This is an example of personification, where the abstract concept of "grace offending" is given human qualities,
3. "To leave his bed, guest his embroidered bed,..."
Embroidered is an example of an adjective used in a figurative sense to denote the ornate quality of the bed.
4. "My soul grows mad with thinking of you..."
This line employs metonymy where "soul" represents the entire person and "mad" is used figuratively to express intense emotional state rather than actual insanity.
5. "...but, like the owner, will upon thy death lie cold and still."
This is another instance of personification, where the "bed" is given human characteristics of an owner that eventually grows cold and still upon death.