The following issues arise when using Power Apps (Preview) in Teams. When "Addition of the column" and "Addition of the table" are done from the edit screen of App, Display Name can be decided by oneself, but Name cannot be decided by oneself.
Therefore, if you use a Multibyte character for ”Display Name", "Name" will be generated automatically as an irregular character.
By the way, if I add a column or table from the Table edit screen, you can enter the "Name" yourself.
Column and Table names are used for management purposes and must be given a readable name. So when you guys release the official version of the app, please make a change so that when I add a column or table from the edit screen of the app, I can also edit Name.