Here is an example of a data grid that uses in-memory data and enables features including pagination, sorting, filtering, column options, row highlighting and column resizing.

All columns, except 'Bronze', have a Tooltip parameter value of true.
When using this for a TemplateColumn (like 'Rank' here), you need to also supply a value for the TooltipText parameter. No value given equals no tooltip shown.
When using this for a PropertyColumn, a value for the TooltipText is not required. By default, the value given for Property will be re-used for the tooltip. If you do supply a value for TooltipText its outcome will be used instead.

TooltipText is a lambda function that takes the current item as input and returns the text to show in the tooltip (and aria-label). Look at the Razor tab to see how this is done and how it can be customized.

The Country filter option can be used to quickly filter the list of countries shown. Pressing the ESC key just closes the option popup without changing the filtering currently being used. Pressing enter finishes the filter action by the current input to filter on and closes the option popup.