akherati

this plugin enable search field in woocommerce attributes when you add OR edit products. 
If you encounter a very large number of attributes when inserting your product attributes, this plugin is for you so you no longer have to spend time finding one attribute out of hundreds of attributes.
this plugin will add good feature to woocommerce so you must install and active woocommerce plugin before that.

fast select Attributes for WooCommerce

You can search and fast select woocommerce attributes of too many attributes in add product page or edit product page.

Andrei Zobnin

This plugin returns the option to choose a product attribute type, which was removed from WooCommerce 3.3. With this plugin you can use select/text/number/textarea type.
WooCommerce requires at least: 3.6

Text Attributes for WooCommerce

Allows you to type attribute values in the input field instead of choosing from the drop-down list.

fast select Attributes for WooCommerce vs Text Attributes for WooCommerce