Read here https://wiki.ubuntu.com/Touch/Porting:
"As Ubuntu Touch is running in a separated container on top of an Android kernel and services, the communication between them happens via Binder, Sockets and libhybris."
Ubuntu touch has a kind of Android based layer where Ubuntu Touch is working on top of it. At least for the first release this will probably the first choice so that many android models can be ported to Ubuntu Touch with reasonable effort.
But this means also that any other device which is not based on android will be very (extremely) difficult to be ported.
Sorry.
I am afraid (or hope so?) that all the answers I found so far, searching for the same question, are simply off topic.
Because x86 tablets are NOT ARM devices, those should be regular PCs with some Intel CPU.
The only points to answer, should be how to get GRUB in, and whether certain hardware has its drivers.
The rest should be the same on tiny 7" x86 tablets, as on any standard desktop - with touch screen, which is just a kind of mouse.
So the partial answer is, NOT ubuntu-touch - do not search for images for ARM CPUs, when yours is Intel x86 (and 64-bit).
What is missing is "howto" make that device boot GRUB (perhaps 32-bit EFI?) on certain tablets, and install Ubuntu - "normal" PC Desktop version.
Well, and onscreen keyboard for touch devices, is part of Ubuntu Desktop, its name is "Onboard". And light desktop environments (xfce4, Xubuntu) may be preferred on tiny devices, to avoid slowdown..
Best Answer
As per the hardware requirements on the OEM partner information page for tablets, there will almost certainly be an x86 version available.