Can't delete a table without deleting the data?

I have Work book that is quite big and I was silly and put in tables, but this ultimately slows down excel so much so that I have to wait 20-30secs while it performs a single task (PC is i7 with 4g of ram).

B/c I have been working on this Workbook for a long time it has multible sheets all interconnected and I can't go through all the sheets and redo the equations , as that wouyld just take too much time. Is there a way of leaving the data the way it is and deleting the table?

This is an example below of the type of table I am talking about.

You should find if you activate the Table and go to Design tab there is an option to "Convert to Range" -- formulae presently using Table[Field] syntax should update to traditional syntax reflecting the conversion from Table to Range.

On an aside, are you sure the slowdown is caused by the Tables ... I'd save a Table version first then convert and save as different version - if performance does not improve you can revert back to Table version and then investigate further (ie look for Volatiles / Array bottlenecks)

Without seeing the thing in full swing it's hard to give advice but what I would say is generally avoid using Arrays in large quantities (includes Sumproduct), avoid using Volatile functions in large quantities (eg INDIRECT,OFFSET etc...)

For more detailed info. on optimisation I would refer to Charles Williams' artcile on msdn:

http://msdn.microsoft.com/en-us/library/aa730921.aspx

and also his own site:

http://www.decisionmodels.com/calcsecrets.htm

but traditionally Volatiles & Arrays are the key contributors to poor performance.