来 as a dummy verb (I'll do it)

"Let me — I'll do it"

• to come来lái can stand in for a real verb, meaning "do it / handle it".
• 我来wǒ lái = "I'll do it"; to let / make让ràngI / me我wǒto come来lái = "let me handle it."
• The context supplies what "to come来lái" actually does.

(to let / make让ràng +) Subj + to come来lái

• to come来lái acts as a dummy "do", taking over the action.

I我wǒ(do it)来lái吧ba。

• 我来wǒ lái(suggestion)吧ba = "let me do it."

Offering to take over

• Often when stepping in: this这个zhè ge我来wǒ lái (I'll take this one).

Recap

Read the full reference: HSK 4 grammar — Verbs.