can load only utf files with out bom to the editor for bult execution,

Can load only files that do not have BOM marking for execution,
files that are UTF-8 encoded with BOM marking shows the following error, i have created two files, one is UTF-8 with BOM and another is
UTF-8 with out BOM, and tested, i shall sent that files if required.

/* Loading file "D:\db_backup\maildb-data-bkup-utf-8-with-bom-file.sql" (1.5 KiB) into query tab #1 ... */
-- MySQL dump 10.13  Distrib 5.1.66, for redhat-linux-gnu (x86_64)
--
-- Host: localhost    Database: maildb

-- ------------------------------------------------------

-- Server version	5.1.66


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/* SQL Error (1064): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-- MySQL dump 10.13  Distrib 5.1.66, for redhat-linux-gnu (x86_64)
--
-- Ho' at line 1 */

/* Affected rows: 0  Found rows: 0  Warnings: 0  Duration for 0 of 22 queries: 0.000 sec. */
/* Error with snippets directory: The specified path was not found */

I can confirm that the BOM is not stripped from UTF-8 files in "Auto-detect" mode and it works unreliably if you specifically select UTF-8 in the "Encoding" combo*.

While it's technically documented ("may fail") and UTF-8 BOM is not supported in lots of apps, it's still a sensible enhancement request. In fact, BOM should help to fine-tune auto-detection.

[*] I've created a couple of test files (with and without BOM). If I select both at the same time, it works fine. If I select only the BOM file, it fails.

Disclaimer: I do not belong to the HeidiSQL developer team.