By default, the number of allowed characters in a single cell is 1,024.
To change the max allowed number of characters in the relevant column:
function modify_content_column(){
global $wpdb;
$wpdb->query("ALTER TABLE {$wpdb->prefix}ifso_bulks_content MODIFY COLUMN content VARCHAR(2048);");
}
add_action('init','modify_content_column');
The code above will change the number of allowed characters to 2,048. You can replace the number in the code with any other number. Bear in mind that if your file consists of a considerable number of dynamic versions, there might be some loading speed implications (they will probably be insignificant, but it is worth checking).