Unfortunately, I don't have a lot of time this week. I might have some on Wednesday. Use the Macro Recorder and record yourself doing the following.
On workbook1, Select column D, right click, Insert column
In C1, enter formula =A1&B1
Autofill the formula down
In workbook2, in B2, enter the formula: =iferror(vlookup($A2&B$1,workbook1$C:$D,2,false),"")
Autofill the formula right
Autofill the formula down
Stop recording
The formula concatenates the date (in column A to the left) and the activity (in row 1 above) and uses that as the criteria to lookup in column C returning the text value in column D. If no match exists (iferror), then nothing is displayed (that is the "" part).
Once the recording is done, post it here, and I can fix it so it works on any size spreadsheet by getting the last row/column.
Best of luck!