Let's take the demo in DevExpress\VCL\Demos\ExpressQuantumGrid\Delphi\FilterDemo as a base.
At the first step, we change the type of "Product" column to TRichViewEdit, and value type to Markdown.
In the Object Inspector, we select TableViewProduct.Properties = "TRichViewEdit", and set TableViewProduct.Properties.EditValueSaveFormat = cxrvvfUnicodeMarkdown.
Also, we set TableView.OptionsView.CellAutoHeight = True.
Now we have "Product" column displayed and edited using TRichViewEdit. Initially, values are stored as plain text, but if you edit some value, it will be saved back as Markdown.
The demo does not have user interface for formatting text, but you can paste text from another rich text editor (such as our RichViewActions demo, or WordPad, or Microsoft Word)
You can see the filter "Express*" (that is created in code), and it works for plain text values. But if you paste a formatted text in some row, like "ExpressFlowChart", it will not match.