Vadim Bogaiskov

Media file (image) does not contain field for title attribute, only for alt attribute.
Plugin add text into title attribute from alt attribute when image is inserted into post if title attribute is empty.
As alternative see plugin <a href="https://wordpress.org/plugins/restore-image-title" rel="ugc">‘Restore Image Title’</a> by Les Bessant. 
The ‘Restore Image Title’ inserted the post title into title attribute.

Title like Alt

Restores the title attribute from Alt attribute when images are inserted into posts

Taylor Callsen

Automatically populates Alt and Title tags for images featured in posts and pages, pulling directly from the values set in the Media Library. This makes it easy to manage your image metadata centrally in one place (the Media Library). Plugin also supports the ability to override the Alt/Title tag Media Library values by placing an Alt/Title tag directly on the attachment in the WordPress WYSIWYG Editor.
Tag population only occurs when viewing the post or page, and does not occur in the WYSIWYG editor.

Auto-populate Image ALT Tags from Media Library

Automatically populates Alt and Title tags for images using the values set in the Media Library.

Title like Alt vs Auto-populate Image ALT Tags from Media Library