The best solution I could find is to use a linear layout(horizontal) for each row you want and within it assign the button (cell) width to 0dp and the weight to 1. For each of the linear layouts(rows) assign the height to 0dp and the weight to 1. Find the code below- also android:layout_gravity="center_vertical" is used to align the buttons in a row in case they contain variable length text. Use of 0dp and weight it a pretty neat yet not so well known trick.
<LinearLayout
android:id="@+id/parent_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/button_bue_3d"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/layout_row1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal" >
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_height="wrap_content"
android:layout_width="0dp"
android:layout_weight="1"
android:clickable="false"
android:layout_gravity="center_vertical"
android:text="ssssssssssssssssssssssssss" />
<Button
android:id="@+id/button2"
style="?android:attr/buttonStyleSmall"
android:clickable="false"
android:layout_height="wrap_content"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_gravity="center_vertical"
android:text="sggggggg" />
</LinearLayout>
<LinearLayout
android:id="@+id/layout_row2"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="0dp"
android:orientation="horizontal" >
<Button
android:id="@+id/button3"
style="?android:attr/buttonStyleSmall"
android:layout_height="wrap_content"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_gravity="center_vertical"
android:text="s" />
<Button
android:id="@+id/button4"
style="?android:attr/buttonStyleSmall"
android:layout_height="wrap_content"
android:layout_width="0dp"
android:layout_weight="1"
android:clickable="false"
android:layout_gravity="center_vertical"
android:text="s" />
</LinearLayout>
</LinearLayout>