Really simple actions attempted here. Create a TextEdit document and stuff text into it.
set theText to "A bunch of text records, each can be 100 characters long, and over 100 records (using returns)..."
tell application "TextEdit"
activate
set txtDoc to make new document with properties {text:theText}
--Fails here with AppleScript Execution Error and TextEdit even crashdumps.
end tell
Further info on the error is:
TextEdit got an error: AppleEvent handler failed.
/System/Applications/TextEdit.app
-10000
???