Populate Autocomplete Field with saved data from Database

Hello,

If you use the custom table of Meta Box, the value will display automatically when you edit a post. If you use your custom table, you can try to use the filter rwmb_{$field_id}_field_meta to change the field value before displaying it in the editing form.

Please read more on the documentation
https://docs.metabox.io/extensions/mb-custom-table/
https://docs.metabox.io/filters/rwmb-field-meta/

Hello,

You can read the list of filters that are supported by Meta Box here https://docs.metabox.io/category/filters/

But I think the filter rwmb_{$field_id}_field_html is a good way to set the field value by coding before displaying it on the editing page.

Or you can use the custom table supported by Meta Box to save the field value to a custom table https://docs.metabox.io/extensions/mb-custom-table/

Otherwise, you should contact an expert developer to help you with your custom table.