Okay, thanks. I managed to get the Developer tab in the ribbon and verify that 'Automatically update styles' was not checked', and check it. That worked... sort of. But there were two problems: (1) Only the text of the caption switched to Calibri. The Label and number (e.g. Table 1) remained Times. And (2) The font size of the text was still 10, not 12. So I inserted a new caption, which seemed to solve the problem (as I recall), but then all my subsequent tables were re-numbered so I closed the doc without saving it. If I try to Modify the current 'Caption' style, it already claims to be Calibri with font size 12.