That looks like a "not built for Python 3.8" error.
Does the -lib package contain both Python 3.7 and 3.8 C extensions (both /usr/lib/python3/dist-packages/tables/utilsextension.cpython-38m-x86_64-linux-gnu.so and /usr/lib/python3/dist-packages/tables/utilsextension.cpython-37m-x86_64-linux-gnu.so - note -38m- vs -37m-)?
If not, check the build log for attempts to build them, and check whether your build chroot was up to date.
The last (failed) build log of the existing 3.5.2-3 suggests it does build them, but it doesn't get far enough to show whether they were installed into the final package.
