For read-only tables displayed as content, data tables as data tables don't need keyboard accessibility in the individual cells. Keyboard-reliant users can generally see the data in the table and visually read it. There's nothing in the individual table data cells containing data that requires interactivity, and thus don't require keyboard focusability. This is typical and expected table behavior.
The exception is if the application puts action buttons or elements into table data cells. Those action elements in the table must be keyboard focusable.
Screen readers provide a way to navigate and read the table data that isn't reliant on keyboard focusability using screen-reader specific keyboard commands. These users can navigate up and down rows and columns with the screen reader to explore the table. Again, this doesn't use keyboard focusability.