Usage

In model class you need to add 'Vdomah.TranslateTabs.Behaviors.TranslateTabbable' behavior to $implement array besides TranslatableModel behavior. Then define translatable attributes as you would do usually with Translate plugin.

public $implement = [
    'RainLab.Translate.Behaviors.TranslatableModel',
    'Vdomah.TranslateTabs.Behaviors.TranslateTabbable',
];

public $translatable = ['name', 'excerpt', 'slug'];

In fields.yaml need to define _translations field like this (exact result of this config you can see on screenshot):

_translations:
    span: left
    type: translations
    form:
        fields:
            name:
                label: Name
                span: auto
                type: text
            slug:
                label: Slug
                span: auto
                preset:
                    field: name
                    type: slug
                type: text
            excerpt:
                label: Excerpt
                span: auto
                type: textarea

Same config works for theme options form in theme.yaml.