What is the Searchable name?
Used to when the the default language of the site is not English and Algolia is used as the site search engine.
Should you be managing a site which default language is not English then it becomes tricky to navigate pages as they need to be listed in the default language for accessibility purposes and how the are discovered by the Algolia search engine.
Searchable name gives you the ability to display the 'Page name' in English within the control panel and then provide the page name in the default language.
Further reading