In table you are working in page-level (not in tasks-level, as in task queries), but I think the inline fields inside tasks working in tasks-level.
So, you can filter by task content (file.tasks.text) or, better, by the field inside tasks (file.tasks.created).
But (always a “but”) as table queries working at page-level you have results per page.
Let’s say you add this:
WHERE contains(file.tasks.created, date(2021-08-09))
This filter is applied to the pages that “contains” this condition, but returns all the tasks inside that pages, not only the wanted tasks.
But, taken the query above, if we add the filter bellow after the FLATTEN file.tasks AS Tasks, maybe it works:
WHERE Tasks.created = date(2021-08-09)