Hmm, I have no idea what the mayo/ketchup thing is. Looking it up on "know your meme" is basically just blank with a video that doesn't exist anymore. Far as I can tell, they are individually both popular condiments in most countries, and using them together is even pretty popular in most countries still. So it must be some specific reference I just can't find?
So, I think I found the correct answer, sadly I had to read a reddit post for it. Apparently, it is someone saying that they'll eat 1 tablespoon of ketchup or mayo for each like their review gets. It's only one source but it was the OP of this meme on /r/Steam (at least the result I found anyway) so maybe that's correct.
What no "WoKe GaMe DoNt BuY!"? Every time I see that I just want to put my hand on their shoulder and say "your mother and I are very disappointed in you son."