Is there a way to get the tables to be published to responsive html5 as separate files in addition to being part of the text, as the image files are?
I need to associate them to separate help buttons.
Since image files are never HTML per se, it sounds like the external/linkable tables only need to be in some file format that browsers know how to display, perhaps PDF.
The tables could be authored as separate .fm files (per table). They would be imported as Text Insets into the main FM document for overall document render. They would also be rendered as each separately, to whatever file format that seems suitable. The main document would have a link at each table to the external table.
The stewardship issues here include:
Until FM gets HTML or XML import, I'm not sure it can get much simpler
In the Publishing Setttings for HTML5 in the Style Mapping tab there is a list of paragraphs. When you select the paragraph format which holds your table anchors, you could activate Split into topics based on this style. Then you should get new files for each table.
If the tables do not need to have a connection to the rest of the document, you could assign a condition to all non-table content and hide this condition, before you publish to HTML5.