The most efficient method to reconcile data in the worksheet to tax slips would be as follows:
Enter the data for both tax years in one worksheet - e.g. 2016-07-01 to 2017-06-30 and 2017-07-01 to 2018-06-30.
A quick check would be to change the tax year in the worksheet to match the calendar year of the slip, and review the Income tab for an agreement to slip totals.
If there are any differences, you can do a more detailed reconciliation by filtering the data on the Worksheet. You can filter by account and date, and/or various types of income to identify contributing transactions for each amount.
e.g. if you filter by "Account 1", for the calendar year on the slip, and by [eligible dividends], you can easily check the sum of those transactions against the amount on the slip.
While entering information, transactions can be entered as "Other - Unknown distribution" and later adjusted on the Income tab to appropriate categories.