I'm assuming you are doing this in Microsoft Word.
Here are the instructions on how to do it:

(1) In the places where you want to enter the text to be repeated, go insert a "Text Form Field". Where this button is depends on whether you are using Word 2003 or 2007.
(2) Select one of the Text Form Fields, go Insert -> Bookmark and give it a descriptive name.
(3) In the places where you want the text to be repeated, go Insert -> Cross Reference. In the "Reference Type" drop down box that shows up, select "Bookmarks". Select the bookmark you created in Step 2.

What you are thinking of are stressor tools and they exists to test a variety of system functions. One memory stressor I've found is from the MSDN magazine: http://msdn.microsoft.com/en-us/magazine/cc163613.aspx

It's called EatMem and is a command line tool written in C# with the source code available in that article. I've compiled the source code and attached it along with the source code in the attachment below. The program is hard coded to stress test the memory by randomly allocating and deallocation between 10%-70% of the memory. You can specify how long it runs for in the command line parameters.

The exe is in the attached file under the \bin\release folders. You need to start up the command line (CMD) in Windows and type in the path to the exe file. For example:
C:\Desktop\TestRun\bin\release\EatMem.exe -d1 will run the program for 1 minute.

Let me know if you need this wrapped up in a graphical interface.

It's doable to track clicks per application but do you want click tracking for all the instances of a single application or just for one open instance. For example, I could program it so that the program just tracks the clicks in one open window of Firefox or I could program it so that it tracks the clicks in all open windows of Firefox. Tracking the clicks in a single window is simpler to program than to track the clicks in all the open windows of a given program.