DataTable tooltip view size

A little late for OP but for everyone having the same issue:

The internal style sheet used by dash has both min-width and max-width set to 300px. If you want to resize the tooltip, you likely have to unset one or both of them.

As an example: the following CSS rules will yield an adaptive-width tooltip with maximum width of 300px

.dash-table-tooltip {
    width: fit-content;
    /* max and min width are both set to 300px in the dash stylesheet. Override them with your own definitions. */
    max-width: 300px;
    min-width: unset;