Most Efficient Way to Write Out Data

I am reading in some large chunks of data and storing them in arrays or a multi-dimensional array.

What is the most efficient way to write out/append that data into a table? Looping and adding rows and then equating individual cells seems very slow to me.

How can we embed an array onto a spreadsheet using vba? In other words converting an array into a range?

(I used to work with Excel using C#, and there was a method which helped converting an array into a range which could be added onto the spreadsheet but I can't seem to find a similar method in vba.)

Many thanks for your help,