So were we, until we took an in-depth look at the issues surrounding memory on the Newton, and how memory cards actually work. RAM is used to store everything else. DRAM and SRAM are faster than FlashRAM, though, and so are better suited to holding certain types of data. Any Newton device's performance is greatly impacted by how much free DRAM it has. Planet Download has a number of shareware and freeware utilities that let you easily freeze and unfreeze packages.
Memory is added to a Newton by inserting a memory PC Card into it.