diff --git a/rich/table.py b/rich/table.py
index 942175dc3a..a1e091f615 100644
--- a/rich/table.py
+++ b/rich/table.py
@@ -9,6 +9,7 @@
     Sequence,
     Tuple,
     Union,
+    Any,
 )
 
 from . import box, errors
@@ -22,7 +23,7 @@
 from .protocol import is_renderable
 from .segment import Segment
 from .style import Style, StyleType
-from .text import Text, TextType
+from .text import Text, TextType, get_unicode_width
 
 if TYPE_CHECKING:
     from .console import (
@@ -422,49 +423,30 @@ def add_column(
 
     def add_row(
         self,
-        *renderables: Optional["RenderableType"],
+        *cells: Any,
         style: Optional[StyleType] = None,
         end_section: bool = False,
     ) -> None:
-        """Add a row of renderables.
-
+        """Add a row to the table.
+        
         Args:
-            *renderables (None or renderable): Each cell in a row must be a renderable object (including str),
-                or ``None`` for a blank cell.
-            style (StyleType, optional): An optional style to apply to the entire row. Defaults to None.
-            end_section (bool, optional): End a section and draw a line. Defaults to False.
-
-        Raises:
-            errors.NotRenderableError: If you add something that can't be rendered.
+            *cells: Cell contents.
+            style: Optional style to apply to the row.
+            end_section: End a section and draw a line. Defaults to False.
         """
-
-        def add_cell(column: Column, renderable: "RenderableType") -> None:
-            column._cells.append(renderable)
-
-        cell_renderables: List[Optional["RenderableType"]] = list(renderables)
-
-        columns = self.columns
-        if len(cell_renderables) < len(columns):
-            cell_renderables = [
-                *cell_renderables,
-                *[None] * (len(columns) - len(cell_renderables)),
-            ]
-        for index, renderable in enumerate(cell_renderables):
-            if index == len(columns):
-                column = Column(_index=index, highlight=self.highlight)
-                for _ in self.rows:
-                    add_cell(column, Text(""))
-                self.columns.append(column)
-            else:
-                column = columns[index]
-            if renderable is None:
-                add_cell(column, "")
-            elif is_renderable(renderable):
-                add_cell(column, renderable)
-            else:
-                raise errors.NotRenderableError(
-                    f"unable to render {type(renderable).__name__}; a string or other renderable object is required"
-                )
+        if len(cells) != len(self.columns):
+            raise ValueError(
+                f"Expected {len(self.columns)} cells, got {len(cells)}"
+            )
+        
+        # Calculate padding for each cell based on Unicode width
+        padded_cells = []
+        for cell, column in zip(cells, self.columns):
+            cell_str = str(cell)
+            width = get_unicode_width(cell_str)
+            padding = " " * (column.width - width) if hasattr(column, 'width') else ""
+            padded_cells.append(cell_str + padding)
+        
         self.rows.append(Row(style=style, end_section=end_section))
 
     def add_section(self) -> None:
diff --git a/rich/text.py b/rich/text.py
index b57d77c276..a40a5ae63f 100644
--- a/rich/text.py
+++ b/rich/text.py
@@ -28,6 +28,7 @@
 from .measure import Measurement
 from .segment import Segment
 from .style import Style, StyleType
+import unicodedata
 
 if TYPE_CHECKING:  # pragma: no cover
     from .console import Console, ConsoleOptions, JustifyMethod, OverflowMethod
@@ -1333,6 +1334,35 @@ def with_indent_guides(
         return new_text
 
 
+def get_unicode_width(text: str) -> int:
+    """Calculate the visual width of a string containing Unicode characters.
+    
+    Args:
+        text (str): The text to measure.
+        
+    Returns:
+        int: The visual width of the text.
+        
+    Example:
+        >>> get_unicode_width("Hello")
+        5
+        >>> get_unicode_width("こんにちは")
+        10
+        >>> get_unicode_width("👋")
+        2
+    """
+    width = 0
+    for char in text:
+        char_width = unicodedata.east_asian_width(char)
+        if char_width in ('F', 'W'):  # Full-width or Wide characters
+            width += 2
+        elif char_width == 'A':  # Ambiguous characters
+            width += 2  # Treat as full-width
+        else:  # Narrow, Half-width, or Neutral characters
+            width += 1
+    return width
+
+
 if __name__ == "__main__":  # pragma: no cover
     from rich.console import Console