Error message I have never seen before

[ajr81]

I am working with a very large workbook with about 15 tabs with, one has a
ton of data nad numerous VLookups. So the size may be where this error is
coming from. Anyway, here is what it says:

"Excel cannot complete this task with available resources. Choose less data
or close other applications."
Has anyone every seen this before? Thanks.

 

[ajr81]

I know how to defrag, and I think I may know how to delete temp folder/files.
How do I make sure I get most of them? Like all the internet things that
are stored. For example, I listen to an online radio and I know that one
time I came across a folder that had the endless list of all the songs. And
I am sure web pages and stored somewhere. Can you get all of those off your
computer? Thanks for your help!