I don't understand the question.
I've used excel for numerous hydrology studies, which is data intensive. A primary consideration is the limit in the number or rows for a worksheet (65536 rows for Excel2002), which you need to compare to the number of data points you will be dumping to the spreadsheet.
For example, if you were to collect a data reading every second you would only be able to accomodate 18.2 hours of data per worksheet.
Also, Excel is probably more of a memory hog than just dumping data to an ASCII text file.
Good luck!