Hi,
The table selector is designed for a very basic table setup, which is not the case here. there are two tables next to each other.
In this case, it will be required to create each header item as a separate selector. See below a reference sitemap to get you started:
{"_id":"NGC-Early-Dimes","startUrl":["https://www.ngccoin.com/census/united-states/dimes/28/"],"selectors":[{"id":"row-table-1","multiple":true,"parentSelectors":["_root"],"selector":"div.pinned tr.ms:not(.hide)","type":"SelectorElement"},{"id":"Year-Mint","multiple":false,"parentSelectors":["row-table-1"],"regex":"","selector":"span.standard","type":"SelectorText"},{"id":"Denom","multiple":false,"parentSelectors":["row-table-1"],"regex":"","selector":"td:nth-of-type(2)","type":"SelectorText"},{"id":"Desig","multiple":false,"parentSelectors":["row-table-1"],"regex":"","selector":"td:nth-of-type(3)","type":"SelectorText"},{"id":"Total","multiple":false,"parentSelectors":["row-table-1"],"regex":"","selector":"td.census-only","type":"SelectorText"},{"extractAttribute":"href","id":"ebay","multiple":false,"parentSelectors":["row-table-1"],"selector":"a.ebay-btn","type":"SelectorElementAttribute"},{"id":"row-table-2","multiple":true,"parentSelectors":["_root"],"selector":"div:not(.pinned) > table tr.ms:not(.hide)","type":"SelectorElement"},{"id":"PrAg","multiple":false,"parentSelectors":["row-table-2"],"regex":"","selector":"td.base.grade-PrAg","type":"SelectorText"},{"id":"grade-G","multiple":false,"parentSelectors":["row-table-2"],"regex":"","selector":"td.base.grade-G","type":"SelectorText"},{"id":"grade-VG","multiple":false,"parentSelectors":["row-table-2"],"regex":"","selector":"td.base.grade-VG","type":"SelectorText"}]}