From this post (velocitygrass, 26th Aug 2014) + additions from the DATA tool v0.0.0.5 source:

• In the Data table unknown0C is the data type (same as the field data flags) and unknown10 is the field_size (for string tables this is 1).

--
FieldDataTypeFlags :

• 0x00000000 Boolean

• 0x00000001 is type string, only used as type in data tables, which are referenced by fields of type 0x0000000B

• 0x00000006 int

• 0x00000007 Tag (uint)

• 0x00000008 Value (ulong)

• 0x00000009 ModifierName (ulong) => CAS Modifier Instance, i.e. Instance ID of a resource of type 0xC5F6763E

• 0x0000000A float

• 0x0000000B VFX => this is actually a string, it's the offset to the actual string in the string table (i.e. the table of type 0x01)

• 0x0000000C => Mode Name (only used in censor tuning), this is string offset + hash of that string

• 0x0000000D => offset to structure based data (and in tables means it's data according to the structure table it has a pos stored to)

• 0x0000000E, Unknown3 => this is a list with the offset to the first element and then the number of elements

• 0x0000000F => two floats

• 0x00000010, RGBColor => three floats, mostly color, but e.g. the padding in the censor bone data is probably dimensions

• 0x00000011 => four floats

• 0x00000012 => Instance ID

• 0x00000013 => TGI

• 0x00000014 => string ID

--
As far as padding goes: I believe the DT header, the individual Data blobs, and the ST header all begin at byte zero, so the 16 bytes line before them is filled with zeroes as needed.

EA template (2015-04): http://forums.thesims.com/en_US/discussion/826671/binary-tuning-sim-data-resource-0x545ac67a-and-0x62e94d38