I need an excel document customising into an access database or similar

General information for the business: We selll energy contracts to businesses
Industry: Business
Analysis tool: Access
Description of analysis: We need to customize the excel data that we pull-off our CRM system so that we can forecast our future revenue. All our revenue is received monthly in arreas over a 1 year period or more. We need to be able paste/import or upload our data so that it can automate the calculation of the following;

1. when the revenues/payments will start and finish
2. how much revenue will be paid each month -(normally the whole revenue shared by the number of months in the contract.
3. bar chart showing the level of income we will receive each month
4. Weighted out to reflect to reflect the majority of income we receive in the winter and the lesser in the summer - we would need to provide you this information so that you can work it out.
5. we must be able to remove/hide or delete the previous data and replace it with the new one.
6. the software must be timeless/ageless and require no customization to extend its capacity
7. The software must be quick, simple to use, and be able handle large amounts date easily without slowing it down.

The current excel data is 72 kB, that could increase by 10% or more each month. If we can include and exclude any of the data at any time that would be ideal.

Please see attached spreadsheet example of what you will be working with


Regards
Ian
Extra notes: