Max Height option is available under Content (tab) > Tooltip > Advanced Settings. This option manages the height of the tooltip content box.
Tooltip content can be set from Markers > Content. If the content is long, tooltip content box will take up a content length. This might look weird and display out of the viewport. In such cases, the height of the tooltip content can be managed with Max height option. This option will set a height for the content box and will add a vertical scroll bar.