Providing local served data via wifi

I want to provide my menu in my little cafe via wifi from my local device for my guests. I don't have an internet connection available.
I tried to set up a hostetnetwork in windows but the problem with this is that I can't provide a password-free hotspot and that they have to type in my local ip.
My question is this:
If I would buy a openwrt router, i.e. I provide an unencrypted hotspot and redirect my customers automatically to a landing page or my html site? If I connect a usb dongle, could I save my site there without the use of a computer?

most of this would probably work fine, the big problem is when mobile devices check for internet and then refuse to connect if the Internet isn't there. however there is a package that fakes all those checking for internet sites. I forget the name but it might be fakeinternet package or similar.

Yes, you can. In case you do not want to provide internet access, too, even no usb-stick required for menu only. With powerful device even order processing possible. Not a trivial job, though, as it also needs to fake internet connection for browsers. Did this as commercial project.

Thanks a lot!
Is there something I have to pay attention when buying a router? The one I mention, because it is very small I am a bit afraid about the output power. Are there differences or can I connect a more powerful USB adapter with big antenna to the usb port?

Try something like this:

a little more capable overall, not a lot more expensive, has a slot to stick an SD card so you can put all your files and things on that. offers dual band.

If you're trying to reach all of a warehouse sized region with one router it could be a problem, but if you put this device centrally located in most any single-story restaurant I've been in, it'd cover the whole thing usually. I certainly got that kind of coverage when I was at a vacation rental with several families. The house was like 4 bedrooms, two levels, with a deck... we could use the travel router from anywhere.

Wow, this looks like a perfect fit!
Thanks a lot,

As a low cost alternative look at zbt we-826.