datatable_test.tcss

TestNodes {
    align: center middle;
}

#datatable {
    height: 50%;
}

#remote_button, #tab-help-button {
    background: green;
    align: center middle;
}

#button-row {
    align: center middle;
}

textual_datatable.py

from textual.app import App, ComposeResult
from textual.containers import Center, Horizontal, Vertical
from textual.widgets import Button, DataTable, Footer

class Test(App):

    CSS_PATH = "datatable_test.tcss"

    def compose(self) -> ComposeResult:
        """
        Create the user interface
        """
        yield Vertical(
            DataTable(id="datatable"),
            Center(
                Horizontal(
                    Button("Remote Desktop", variant="primary", id="remote_button"),
                    Button("Report Issue", variant="error", id="report_button"),
                    id="button-row"
                )
            ),
            id="main_tab"
        )
        yield Footer()

    def on_mount(self) -> None:
        ROWS = [("No Data Found", "", ""), ("Press CTRL+L to load CSV file", "", "")]
        table = self.query_one(DataTable)
        table.add_columns(*ROWS[0])
        table.add_rows(ROWS[1:])

app = Test()
app.run()