On thesaurii, we have the tooltip view that generating a tooltip in the tree.
This tooltip is not optimal so each element is long to load. Only few elements can takes several seconds. If we have a "lot" (maybe 50) elements, it can take over than a minute.
Take a look to: org.ametys.cms.content.referencetable.GetHierarchicalReferenceTablesAction._getTooltip(Content)