I use QComboBox, that shows a list of the parameter variants. QComboBox is connected to the QTableWidget as a delegate.

Okay, I understand why this might get complicated. In a lot of cases it is sufficient to be able to compare the text that was read in from the file with a specific string (where we can use the translated string again).

In your case, I suggest the following: For each entry in the QComboBox add the non-translated text as user data. When adding items you can use QComboBox::addItem(tr(text),text). When the user selects something you get back the non-translated string using comboBox->itemData(comboBox->currentIndex()).toString(). Now, it gets slightly more complicated: Change from a QTableWidget to a QTableView. This also means that you need to write your own model class derived from QAbstractItemModel. Inside the model store the non-translated texts. The magic now happens with your derived class which needs to override data(...). For the DisplayRole of this function you then return the translated string, i.e. only when displaying the string in the table will you translate the text and everything before that is the non-translated text. You can then still get out the non-translated text from the model (your own derived class) and store this in your xml file.

I use QComboBox, that shows a list of the parameter variants. QComboBox is connected to the QTableWidget as a delegate.

Okay, I understand why this might get complicated. In a lot of cases it is sufficient to be able to compare the text that was read in from the file with a specific string (where we can use the translated string again).

In your case, I suggest the following: For each entry in the QComboBox add the non-translated text as user data. When adding items you can use QComboBox::addItem(tr(text),text). When the user selects something you get back the non-translated string using comboBox->itemData(comboBox->currentIndex()).toString(). Now, it gets slightly more complicated: Change from a QTableWidget to a QTableView. This also means that you need to write your own model class derived from QAbstractItemModel. Inside the model store the non-translated texts. The magic now happens with your derived class which needs to override data(...). For the DisplayRole of this function you then return the translated string, i.e. only when displaying the string in the table will you translate the text and everything before that is the non-translated text. You can then still get out the non-translated text from the model (your own derived class) and store this in your xml file.

If you are using QTranslator, it's a one way translation from the original text in code to the one provided by QTranslator.

You need to provide more information about your text table. What is it ? Is it user modifiable ? How do you save and restore it ?