Page gets timed out when a "Catalog Task" activity is added to a new workflow.

Too many records on "item_option_new"  table.

While creating a new workflow, All the variables on "item_option_new" are displayed. As there are millions of records , the page is not loaded or timed out.

If the workflow is already associated to a catalog item, then only the variables that are on that item are shown.

This logic is controlled by a business rule "workflow item variables" on "addDefaultVariables" function. Reduce the number of variables on "item_option_new"  table.
Below is logic:

function addDefaultVariables(variables) {
   var itemVars = new GlideRecord('item_option_new');
   itemVars.addNotNullQuery('name');
   itemVars.query();
   while (itemVars.next()) {
       if (itemVars.name != '') {
          variables[itemVars.name.toString()] = itemVars.name.toString();
       }
   }
}