See the help topic Horizontal Curves, Entering Curves as you go.
TPC assumes curves are tangent unless you tell it otherwise by entering any data that specifies the orientation of the curve. These would be incoming direction (PC->PI), PC->PR direction, chord bearing, etc. All of these are most easily done while entering the curve in the Traverse View, but you have to include those columns in the traverse view format. In the Curve dialog, you have to learn about holding/releasing curve data to accomplish this.
Multiple Line Tables
TPC currently allows just one table of each type (Lines, Curves, Lots, Points). We will be adding the ability for multiple tables soon.
Editing Table Data
To edit any table data, just right click it in the table.
You can also add record data by appending a ; to the end of the table entry while editing it, then adding your record data after that.