"Do you travel a lot?"
They both indicate a large number/amount. Using "αρκετά" exclusively to mean "enough" can get you in linguistic trouble. "Enough" means "as much/many as is/are required" thus implying surpassing a fixed amount as in: "Do we have enough chairs for all the guests?" which means "Will each guest have a chair." "Are there as many chairs as there are guests."
That is too often rendered in Greek with "ακεκτά" resulting in e.g: "Είχαμε αρκετές καρέκλες αλλά μερικοί δεν είχαν μια καρέκλα." being translated as "We had enough chairs but some people didn't have a chair." which is illogical. If you had enough (as many chairs as were required) why didn't everyone have one? What is really meant here is "We had a lot of chairs...."
So, yes "αρκετά" can mean "enough" or "a lot" just be careful where you use it.