I was just pasting some data over from one worksheet to another in the same file. The destination worksheet contains a few thousand VLOOKUP formula. When I paste the data over, it takes quite a few minutes to complete the paste. This is because Excel keep re-calculating the VLOOKUP formulas as the data get pasted over. In this case, you can either turn of auto-calculation which I don’t like to do because I usually forget to turn on after that. The other way is to use MSQuery to link the data together. The third and newer way is to use PowerPivot which can perform the calculation at a faster rate without the re-calculation problem.