Tables and Cards
Tables can show aggregated (summarized) or non-aggregated data in a grid with columns and rows.
Tables by Microsoft
Cards just show one value. For a quantitative value that is an aggregate or summarization - it could be a count , average, minimum, etc...For qualitative, it is one value from the set - first or last, earliest or latest or a custom metric. Apart from the custom metric, these will depend on how they are sorted.
Cards by Microsoft