diff --git a/sdv/metadata/metadata.py b/sdv/metadata/metadata.py
index fc3942a26..537d8bba2 100644
--- a/sdv/metadata/metadata.py
+++ b/sdv/metadata/metadata.py
@@ -70,6 +70,10 @@ def _set_metadata_dict(self, metadata, single_table_name=None):
         else:
             if single_table_name is None:
                 single_table_name = self.DEFAULT_SINGLE_TABLE_NAME
+                warnings.warn(
+                    'No table name was provided to metadata containing only one table. '
+                    f'Assigning name: {single_table_name}'
+                )
             self.tables[single_table_name] = SingleTableMetadata.load_from_dict(metadata)
 
     def _get_single_table_name(self):
diff --git a/sdv/metadata/multi_table.py b/sdv/metadata/multi_table.py
index 7c6e2a17e..38224da59 100644
--- a/sdv/metadata/multi_table.py
+++ b/sdv/metadata/multi_table.py
@@ -409,6 +409,8 @@ def update_columns(self, table_name, column_names, **kwargs):
             **kwargs:
                 Any key word arguments that describe metadata for the columns.
         """
+        if not isinstance(column_names, list):
+            raise InvalidMetadataError('Please pass in a list to column_names arg.')
         self._validate_table_exists(table_name)
         table = self.tables.get(table_name)
         table.update_columns(column_names, **kwargs)
@@ -832,8 +834,8 @@ def validate_data(self, data):
             * all foreign keys belong to a primay key
 
         Args:
-            data (pd.DataFrame):
-                The data to validate.
+            data (dict):
+                A dictionary of table names to pd.DataFrames.
 
         Raises:
             InvalidDataError:
@@ -843,6 +845,9 @@ def validate_data(self, data):
             A warning is being raised if ``datetime_format`` is missing from a column represented
             as ``object`` in the dataframe and its sdtype is ``datetime``.
         """
+        if not isinstance(data, dict):
+            raise InvalidMetadataError('Please pass in a dictionary mapping tables to dataframes.')
+
         errors = []
         errors += self._validate_missing_tables(data)
         errors += self._validate_all_tables(data)
@@ -880,7 +885,7 @@ def get_column_names(self, table_name, **kwargs):
 
         Args:
             table_name (str):
-                The name of the table to get column names for.s
+                The name of the table to get column names for.
             **kwargs:
                 Metadata keywords to filter on, for example sdtype='id' or pii=True.
 
diff --git a/sdv/multi_table/base.py b/sdv/multi_table/base.py
index f722826dd..3978bddf1 100644
--- a/sdv/multi_table/base.py
+++ b/sdv/multi_table/base.py
@@ -77,7 +77,8 @@ def _initialize_models(self):
         with disable_single_table_logger():
             for table_name, table_metadata in self.metadata.tables.items():
                 synthesizer_parameters = self._table_parameters.get(table_name, {})
-                metadata = Metadata.load_from_dict(table_metadata.to_dict())
+                metadata_dict = {'tables': {table_name: table_metadata.to_dict()}}
+                metadata = Metadata.load_from_dict(metadata_dict)
                 self._table_synthesizers[table_name] = self._synthesizer(
                     metadata=metadata, locales=self.locales, **synthesizer_parameters
                 )
diff --git a/tests/unit/metadata/test_multi_table.py b/tests/unit/metadata/test_multi_table.py
index a43816100..e3634d503 100644
--- a/tests/unit/metadata/test_multi_table.py
+++ b/tests/unit/metadata/test_multi_table.py
@@ -3064,3 +3064,42 @@ def test_anonymize(self, mock_load):
             'parent_primary_key': 'col1',
             'child_foreign_key': 'col2',
         }
+
+    def test_update_columns_no_list_error(self):
+        """Test that ``update_columns`` only takes in list and that an error is thrown."""
+        # Setup
+        metadata = MultiTableMetadata()
+        metadata.add_table('table')
+        metadata.add_column('table', 'col1', sdtype='numerical')
+
+        error_msg = re.escape('Please pass in a list to column_names arg.')
+        # Run and Assert
+        with pytest.raises(InvalidMetadataError, match=error_msg):
+            metadata.update_columns('table', 'col1', sdtype='categorical')
+
+    def test_validate_data_without_dict(self):
+        """Test that ``validate_data`` only takes in dict and that an error is thrown otherwise."""
+        # Setup
+        metadata = MultiTableMetadata.load_from_dict({
+            'tables': {
+                'table_1': {
+                    'columns': {
+                        'col_1': {'sdtype': 'numerical'},
+                        'col_2': {'sdtype': 'categorical'},
+                        'latitude': {'sdtype': 'latitude'},
+                        'longitude': {'sdtype': 'longitude'},
+                    }
+                }
+            }
+        })
+        data = pd.DataFrame({
+            'col_1': [1, 2, 3],
+            'col_2': ['a', 'b', 'c'],
+            'latitude': [1, 2, 3],
+            'longitude': [1, 2, 3],
+        })
+        error_msg = re.escape('Please pass in a dictionary mapping tables to dataframes.')
+
+        # Run and Assert
+        with pytest.raises(InvalidMetadataError, match=error_msg):
+            metadata.validate_data(data)