The table indicates the average family expenditure that expends monthly in Australia between 1991 and 2001
The table illustrates the changes in monthly spending of an average Australian household between 1991 and 2001.
At a glance, it can be seen that
I feel that both "At a glance" and "It can be seen that" mean the same. You could simply write "Overall".
expenditure in Food was by far more than other appliances.
I think that "other goods and services" were the biggest item of expenditure.
In the overview paragraph, you could indicate the change in total spending instead, for example: Overall, there was a rise in the total expenditure of an Australian family from 1991 to 2001.
The biggest increase of expenditure was in consuming Food which more than doubled over the period
It is not correct. Actually, electricity and water consumption experienced the most significant increase over the period.
The largest number of expenditure in total
This sentence is not aligned with your overview.
There were almost as much expensive in Transport as in Electricity and Water in 1991
I don't quite get what you mean here and I don't think "expensive" is the right word.
I hope this helps!