I'm not finding answers on this in searches. Here's the context:
At work we use several custom tables I created, originally in W2010 or 2013, in a custom template. Today, in reviewing a proposal document from a client into which we were obliged to insert our response, though in our own formats, I came across instances in our custom tables in which the table text style, required to be 11 pt, which I had therefore increased from 10 in the style in that document, was not being applied; the text stubbornly stayed at 10 pt, even when formatted for 11 adn showing 11 in both style and local formatting. I determined that the custom table style had 10 pt built-in, something I had done originally and not recalled; but I was able to modify the table style by right-clicking the table style (I keep the table styles gallery in my QAT), and all was well.



Realizing this problem might come up again, I later opened my copy of our custom template, stored on my computer, to make the same modification (i.e., removing specification of point size) in the offending table, only to find "Modify table style" greyed out for all three custom tables, whether I opened the template or a document based on it. Why I should have been able to modify the table style from a document on SharePoint baffles me, except that it divorces documents from custom templates.

Short of recreating the table styles, is there no way to modify them? They are not locked, the template is not read-only, etc.