I’m trying to format some cells in writer, and the character format dialog shows me asian characters together with my selected text. I couldn’t find an option to remove the asian format typography in the dialog and its preview.
You didn’t tell if your document is intended to contain Western+Asian text. And your screen shot shows you even have “complex text” (Hebrew, Arabic and various Indian/South East Asia scripts) enabled.
In case you only write Western, go to Options>Tools (for W$ and Linux; Preferences for MacOS), Languages & Locales>General and untick Asian and Complex text layout in Default Languages for Documents.
PS: due to subtle differences, always mention OS name, exact LO version and, when relevant, save format.