I've been doing some Wordpress theme development recently, and I couldn't find a decent reference for the blocks that come with the default Wordpress editor. So I'll keep one here.

Disabling blocks in the Post Editor

These identifiers are useful because they let you define a limited set of blocks that will be available in the post editor from your functions.php file.

function theme_allowed_block_types($allowed_block_types){
    return array(
		'core/paragraph',
		'core/heading',
        'core/list'
        # Add more identifiers here
	);
}
add_filter('allowed_block_types', 'theme_allowed_block_types');

In addition to this, I like to disable the default block CSS and style them myself instead. You do that by attaching a function to the wp_print_styles hook:

function remove_block_css()
{
	wp_deregister_style('wp-block-library');
}
add_action('wp_print_styles', 'remove_block_css');