Want to create vba function or macro to paste a value to certain range

I have got got a large amount or data for processing.
problem is i have to do repeated thins like convert COL-A to COL-B.

Is it possible to convert COL-A to COL-B of large amount of data in a column.

sample problem is provided below.

COLUMN A COLUMN B
pencil pencil
" pencil
" pencil
" pencil
" pencil
" pencil
" pencil
" pencil
pen pen
" pen
" pen
" pen
" pen
Book Book
" Book
" Book
" Book