The long text and text area field shows more saved search results and it is by standard behavior. we can “export” to Excel, the Saved Search Results and all the text will be returned.
Upon checking, there’s no available workaround yet for the value of a custom field on saved search to be displayed in full. This behavior is still logged as an enhancement (Enhancement 102873: Setup>Customization>Record Types > Custom Field> If a custom field is created with type = Long text, and filled it up with more than 250 characters, when you do a search and display this custom field then it truncates the data encoded.).
As a temporary workaround.
Instead of using the original Text Area custom field in the Saved Search, I used a Formula (Text) field with the custom Text Area field, internal id in the Formula field. The full text of the custom Text Area field are displayed.
It is a redundant exercise to create a custom Text Area field, then have to use a Formula (Text) to retrieve all the field text in a Saved Search.