This is a tough one for a number of reasons. E-ink displays are traditionally way too slow for practical use in the capacity that you're talking about, the refresh rate is way too long and you end up with artifacts on the screen. I've tried this myself with an e-reader, it was not a good experience. This thread details some similar experiences, if that helps lend any credibility:
So we've identified a problem, let's focus on a solution. I warn you now it is not cheap, but it's really the only thing that is going to do what you're asking it to do and it's all I've been able to find the past two days of hunting.
That monitor is pretty much the only thing you're going to find that will provide a usable experience with a full operating system (Windows, iOS, etc.). Obviously it will also do the trick for reading. It is specifically designed from the ground up to be a functional e-ink monitor, and utilizes new technology and algorithms to improve response time and give the user control over features and settings. It is portable, though large.
The newer revision is $1k, the old one isn't much cheaper. The newer one does have one major portability advantage in that a single HDMI cord can provide picture and power to the monitor.
Here's where things get tricky. You'll need a computer, some sort of input device(s), and a method of generating power. There are a lot of ways to get creative with this, but again few of them are cheap.
You could go the laptop route, but it'd be unwieldy. I guess something like a raspberry pi or an intel compute stick might work in conjunction, but you'd likely be forced into having access to a power outlet so also not ideal. As far as input devices, there are a wide range of wireless input mechanisms available to you. These would be best selected after you figure out the computer portion of this portable system, so you know what kind of I/O options you're looking at. All of that stuff is better left for a different (and more specific) question here on HardwareRecs.
To wrap all this up with a direct answer:
Is there a tablet/notebook, that runs a normal operating system (like windows or iOS, or Ubuntu), where you can open word processors, chrome, and so forth, which has an e-ink display (and is cheap)?
No, there is not. Your best bet would be to build something yourself if you think yourself capable. You'll likely end up dropping well over $1,000 USD in the endeavor, because anything less than the e-ink monitor listed above will not function in a useful capacity due to limitations of the technology. It's not impossible, but it's a tall order. Best of luck.