Test Complete runs scripts, not compiled code, so it kind of needs to go through the process of loading all the scripts at runtime, hence the start up delay.
Question: when you say your Excel files are your scripts, what do you mean? Are they just tables of data or do they contain some sort of code?
The reason I ask is that a solution could be to code a framework of sorts that will read an Excel file, parse it for commands, execute, and then report out the results, repeat in a loop for each file. Rather than adding 800+ files to TestComplete, invest some time in writing some code to allow you to keep the Excel files as is and let them operate as your drivers for the actual tests. ULtimately, your code base will be less than the 800+ files and so your memory footprint will be considerably smaller.
