Fix _table_mod is 'NoneType' issue
- [x] closes #27253 
- [ ] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Currently in get_node() it is not guaranteed that _table_mod is not none, and this breaks some packages that depend on Pandas, forcing use of older versions of Pandas. I added `_tables()` to fix this issue
see #27253 for more details
closing; suclasses are not following the api of HDFStore; would take a patch with proper tests. (though I don't see any good reason to actually subclass HDFStore).