Why does my data file use up more RAM than expected?

You may open a data file and find that it uses up much more RAM than expected. For example, a 1MB file uses up 8MB of RAM after being opened.

This could happen if the data file has a large number of empty cells. These cells do not take any space when saving the file, but they use up the memory when the file is opened. If you filled all of the cells with data and saved the file, you would see that the size of the file would increase dramatically.