How to add / remove columns in Woocommerce admin product list

The filter manage_edit-{post_type}_columns is only used to actually add the column. To control what is displayed in the column for each post (product), you can use the manage_{post_type}_posts_custom_column action. This action is called for each custom column for every post, and it passes two arguments: $column and $postid.

Using this action is quite easy, you can find an example to display the custom field "offercode" below:

add_action( 'manage_product_posts_custom_column', 'wpso23858236_product_column_offercode', 10, 2 );function wpso23858236_product_column_offercode( $column, $postid ) {    if ( $column == 'offercode' ) {        echo get_post_meta( $postid, 'offercode', true );    }}

You could also use a plugin to control this behaviour, such as Admin Columns.

this table view is used by many plugins and wordpress itself. You have to check the column name. $columns['tags'] is the tag in Wordpress Post View, not in Woocommerce!

Here is a list of some $columns used by Woocommerce:

$columns['cb']  $columns['thumb']$columns['name'] $columns['sku'] $columns['is_in_stock']$columns['price']$columns['product_cat'] $columns['product_tag']$columns['featured']$columns['product_type']$columns['date']

and that is the correct filter to apply these removals.

add_filter( 'manage_edit-product_columns', 'change_columns_filter',10, 1 );function change_columns_filter( $columns ) {unset($columns['product_tag']);unset($columns['sku']);unset($columns['featured']);unset($columns['product_type']);return $columns;}

If you additionally want to sort the columns (as shown above, your column will just be attached to the end), you can do something like that in your hook of "manage_edit-product_columns" (example is taken from a class I've implemented):

const BACKEND_PRODUCT_GRID_FIELD_SORTORDER = [    'cb',    'thumb',    'name',    'pa_size_text',    'sku',    'is_in_stock',    'price',    'product_cat',    'product_tag',    'featured',    'product_type',    'date',    'stats',    'likes'];/** * Registers new columns for the backend products grid of Woocommerce. * Additionally it sorts the fields after * self::BACKEND_PRODUCT_GRID_FIELD_SORTORDER. Fields not included in * self::BACKEND_PRODUCT_GRID_FIELD_SORTORDER will be attached to the end of * the array. * * @param array $aColumns - the current Woocommerce backend grid columns * * @return array - the extended backend grid columns array */public function add_columns_to_product_grid( $aColumns ) {    $aColumns['pa_size_text'] = __( 'Unit size', 'intolife_misc' );    #unset($aColumns['thumb']);    $aReturn = [];    foreach ( self::BACKEND_PRODUCT_GRID_FIELD_SORTORDER as $sKey ) {        if ( isset( $aColumns[ $sKey ] ) ) {            $aReturn[ $sKey ] = $aColumns[ $sKey ];        }    }    /**     * search additional unknown fields and attache them to the end     */    foreach ( $aColumns as $sKey => $sField ) {        if ( ! isset( $aReturn[ $sKey ] ) ) {            $aReturn[ $sKey ] = $sField;        }    }    return $aReturn;}