Table tooltips are currently a bit messy. They work great for providing visibility into supporting data, calculations, etc. that don't fit in the table columns, but it's annoying for the user to always have a popup when they're hovering anywhere over the table, which they must be when scrolling. Additionally, sometimes only certain rows have supporting information (such as notes), so that it doesn't make sense to show the tooltip for all rows.
This idea doesn't solve all of these problems, but it does at least address a common scenario with the overlap of them.
Conditional formatting icons are great for informing the users that "something is different about this row." This prompts them to hover to view the tooltip. Making the icon have a click action that displays the tooltip would be intuitive for the user, avoids the problem of showing tooltips for rows that have no additional information, and keeps the user from getting frustrated at the pop-up.
